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Comparably little is known about breast cancer (BC) risks in women from families tested negative for BRCA1/2 mutations despite an indicative family history, as opposed to BRCA1/2 mutation carriers. We determined the age-dependent risks of first and contralateral breast cancer (FBC, CBC) both in noncarriers and carriers of BRCA1/2 mutations, who participated in an intensified breast imaging surveillance program. The study was conducted between January 1, 2005, and September 30, 2017, at 12 university centers of the German Consortium for Hereditary Breast and Ovarian Cancer. Two cohorts were prospectively followed up for incident FBC (n = 4,380; 16,398 person-years [PY], median baseline age: 39 years) and CBC (n = 2,993; 10,090 PY, median baseline age: 42 years). Cumulative FBC risk at age 60 was 61.8% (95% CI 52.8-70.9%) for BRCA1 mutation carriers, 43.2% (95% CI 32.1-56.3%) for BRCA2 mutation carriers and 15.7% (95% CI 11.9-20.4%) for noncarriers. FBC risks were significantly higher than in the general population, with incidence rate ratios of 23.9 (95% CI 18.9-29.8) for BRCA1 mutation carriers, 13.5 (95% CI 9.2-19.1) for BRCA2 mutation carriers and 4.9 (95% CI 3.8-6.3) for BRCA1/2 noncarriers. Cumulative CBC risk 10 years after FBC was 25.1% (95% CI 19.6-31.9%) for BRCA1 mutation carriers, 6.6% (95% CI 3.4-12.5%) for BRCA2 mutation carriers and 3.6% (95% CI 2.2-5.7%) for noncarriers. CBC risk in noncarriers was similar to women with unilateral BC from the general population. Further studies are needed to confirm whether less intensified surveillance is justified in women from BRCA1/2 negative families with elevated risk.

The X and Y sex chromosomes of placental mammals show hallmarks of a tumultuous evolutionary past. The X Chromosome has a rich and conserved gene content, while the Y Chromosome has lost most of its genes. In the Transcaucasian mole vole Ellobius lutescens, the Y Chromosome including Sry has been lost, and both females and males have a 17,X diploid karyotype. Similarly, the closely related Ellobius talpinus, has a 54,XX karyotype in both females and males. Here, we report the sequencing and assembly of the E. lutescens and E. talpinus genomes. The results indicate that the loss of the Y Chromosome in E. lutescens and E. talpinus occurred in two independent events. Four functional homologs of mouse Y-Chromosomal genes were detected in both female and male E. lutescens, of which three were also detected in the E. talpinus genome. One of these is Eif2s3y, known as the only Y-derived gene that is crucial for successful male meiosis. Female and male E. lutescens can carry one and the same X Chromosome with a largely conserved gene content, including all genes known to function in X Chromosome inactivation. The availability of the genomes of these mole vole species provides unique models to study the dynamics of sex chromosome evolution.

Background Borjeson–Forssman–Lehmann syndrome (BFLS) is an X-linked recessive intellectual disability (ID) disorder caused by mutations in the PHF6 gene and characterised by variable cognitive impairment, a distinct facial gestalt, obesity, and hypogonadism. Female carriers are usually not affected or only mildly affected, and so far only two females with de novo mutations or deletions in PHF6 have been reported. Methods and results We performed PHF6 mutational analysis and screening for intragenic deletions and duplications by quantitative real-time PCR and multiplex ligation dependent probe amplification (MLPA) in female patients with variable ID and a distinct appearance of sparse hair, remarkable facial features, hypoplastic nails, and teeth anomalies. We detected two truncating mutations and two duplications of exons 4 and 5. Furthermore, two female patients with PHF6 deletions and a similar phenotype were identified by routine molecular karyotyping. Recently, two patients with a clinical diagnosis of Coffin-Siris syndrome in early infancy had been found to harbour mutations in PHF6 , and their phenotype in advanced ages is now described. Further studies revealed skewed X-inactivation in blood lymphocytes, while it was normal in fibroblasts, thus indicating functional mosaicism. Conclusions Our findings indicate that de novo defects in PHF6 in females result in a recognisable phenotype which might have been under-recognised so far and which comprises variable ID, a characteristic facial gestalt, hypoplastic nails, brachydactyly, clinodactyly mainly of fingers IV and V, dental anomalies, and linear skin hyperpigmentation. It shows overlap with BFLS but also additional distinct features, thus adding a new facet to this disorder.

PURPOSE: Cis-acting regulatory SNPs resulting in differential allelic expression (DAE) may, in part, explain the underlying phenotypic variation associated with many complex diseases. To investigate whether common variants associated with DAE were involved in breast cancer susceptibility among BRCA1 and BRCA2 mutation carriers, a list of 175 genes was developed based of their involvement in cancer-related pathways. METHODS: Using data from a genome-wide map of SNPs associated with allelic expression, we assessed the association of ~320 SNPs located in the vicinity of these genes with breast and ovarian cancer risks in 15,252 BRCA1 and 8211 BRCA2 mutation carriers ascertained from 54 studies participating in the Consortium of Investigators of Modifiers of BRCA1/2. RESULTS: We identified a region on 11q22.3 that is significantly associated with breast cancer risk in BRCA1 mutation carriers (most significant SNP rs228595 p = 7 × 10-6). This association was absent in BRCA2 carriers (p = 0.57). The 11q22.3 region notably encompasses genes such as ACAT1, NPAT, and ATM. Expression quantitative trait loci associations were observed in both normal breast and tumors across this region, namely for ACAT1, ATM, and other genes. In silico analysis revealed some overlap between top risk-associated SNPs and relevant biological features in mammary cell data, which suggests potential functional significance. CONCLUSION: We identified 11q22.3 as a new modifier locus in BRCA1 carriers. Replication in larger studies using estrogen receptor (ER)-negative or triple-negative (i.e., ER-, progesterone receptor-, and HER2-negative) cases could therefore be helpful to confirm the association of this locus with breast cancer risk. Funding for the iCOGS infrastructure came from the European Community's Seventh Framework Programme under Grant Agreement No. 223175 (HEALTH-F2-2009-223175) (COGS), Cancer Research UK (C1287/A10118, C1287/A 10710, C12292/A11174, C1281/A12014, C5047/A8384, C5047/A15007, C5047/A10692, C8197/A16565), the National Institutes of Health (CA128978) and Post-cancer GWAS Initiative (1U19 CA148537, 1U19 CA148065, and 1U19 CA148112: the GAME-ON Initiative), the Department of Defence (W81XWH-10-1-0341), the Canadian Institutes of Health Research (CIHR) for the CIHR Team in Familial Risks of Breast Cancer, Komen Foundation for the Cure, the Breast Cancer Research Foundation, and the Ovarian Cancer Research Fund. BCFR: this work was supported by Grant UM1 CA164920 from the National Cancer Institute. BFBOCC was supported by Lithuania (BFBOCC-LT): Research Council of Lithuania Grant SEN-18/2015. BIDMC was supported by the Breast Cancer Research Foundation. BRCA-gene mutations and breast cancer in South African women (BMBSA) was supported by Grants from the Cancer Association of South Africa (CANSA) to Elizabeth J. van Rensburg. BRICOH: SLN was partially supported by the Morris and Horowitz Families Endowed Professorship. CNIO: this work was partially supported by Spanish Association Against Cancer (AECC08), RTICC 06/0020/1060, FISPI08/1120, Mutua Madrilena Foundation (FMMA), and SAF2010-20493. COH-CCGCRN: patients were recruited for this study from the City of Hope Clinical Cancer Genomics Community Research Network, supported in part by Award Number RC4CA153828 (PI: J. Weitzel) from the National Cancer Institute and the Office of the Director, National Institutes of Health. CONSIT Team: Associazione Italiana Ricerca sul Cancro (AIRC) to P. Peterlongo (IG 2012 Id. 12821) and P. Radice (IG 2014 Id. 15547). Funds from Italian citizens who allocated the 5 9 1000 share of their tax payment in support of the Fondazione IRCCS Istituto Nazionale Tumori, according to Italian laws (INT-Institutional Strategic Projects '5x1000') to S. Manoukian. FiorGen Foundation for Pharmacogenomics to L. Papi. CORE: the CIMBA Data Management and Data Analysis were supported by Cancer Research: UK Grants C12292/A20861, C12292/A11174. ACA is a Cancer Research-UK Senior Cancer Research Fellow. GCT is an NHMRC Senior Principal Research Fellow. J. Lecarpentier has been financially supported by the Fondation ARC (FONDATION ARC, 9 rue Guy Moquet 94803 Villejuif: France), Grant Number SAE20131200623. This work was supported by the Canadian Institutes of Health Research for the "CIHR Team in Familial Risks of Breast Cancer" Program: Grant No. CRN-87521 and the Ministry of Economic Development, Innovation and Export Trade: Grant No. PSR-SIIRI-701. The PERSPECTIVE Project was supported by the Government of Canada through Genome Canada and the Canadian Institutes of Health Research, the Ministere de l'Economie, Innovation et Exportation du Quebec through Genome Quebec, and The Quebec Breast Cancer Foundation. This work was also supported by the Ministere de l'Economie, Innovation et Exportation du Quebec: Grant No. PSR-SIIRI-701. DEMOKRITOS: this research has been co-financed by the European Union (European Social Fund: ESF) and Greek National Funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF): Research Funding Program of the General Secretariat for Research and Technology: SYN11_10_19 NBCA. Investing in Knowledge Society through the European Social Fund. The DKFZ Study was supported by the DKFZ. EMBRACE was supported by Cancer Research UK Grants C1287/A10118 and C1287/A11990. D. Gareth Evans and Fiona Lalloo were supported by an NIHR Grant to the Biomedical Research Centre, Manchester. The Investigators at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust were supported by an NIHR Grant to the Biomedical Research Centre at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust. Ros Eeles and Elizabeth Bancroft were supported by Cancer Research UK Grant C5047/A8385. Ros Eeles was also supported by NIHR support to the Biomedical Research Centre at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust. FCCC: the authors acknowledge the support from The University of Kansas Cancer Center (P30 CA168524) and the Kansas Bioscience Authority Eminent Scholar Program. A.K.G. was funded by 5U01CA113916, R01CA140323, and by the Chancellors Distinguished Chair in Biomedical Sciences Professorship. The German Consortium of Hereditary Breast and Ovarian Cancer (GC-HBOC) was supported by the German Cancer Aid (Grant No. 110837, Rita K. Schmutzler). This work was supported by the European Regional Development Fund and Free State of Saxony, Germany (LIFE: Leipzig Research Centre for Civilization Diseases, Project Numbers 713-241202, 713-241202, 14505/2470, 14575/2470). GEMO: the study was supported by the Ligue Nationale Contre le Cancer; the Association "Le cancer du sein, parlons-en!" Award; the Canadian Institutes of Health Research for the "CIHR Team in Familial Risks of Breast Cancer" Program and the French National Institute of Cancer (INCa). GEORGETOWN: CI received support from the Non-therapeutic Subject Registry Shared Resource at Georgetown University (NIH/NCI Grant P30-CA051008), the Fisher Center for Hereditary Cancer and Clinical GenomicsResearch, and Swing Fore the Cure. G-FAST: Bruce Poppe is a Senior Clinical Investigator of FWO. Mattias Van Heetvelde obtained funding from IWT. HCSC was supported by a Grant RD12/0036/0006 and 15/00059 from ISCIII (Spain), partially supported by European Regional Development FEDER Funds. The HEBCS was financially supported by the Helsinki University Hospital Research Fund, Academy of Finland (266528), the Finnish Cancer Society and the Sigrid Juselius Foundation. HEBON Study was supported by the Dutch Cancer Society Grants NKI1998-1854, NKI2004-3088, and NKI2007-3756, the Netherlands Organization of Scientific Research Grant NWO 91109024, the Pink Ribbon Grants 110005 and 2014-187.WO76, the BBMRI Grant NWO 184.021.007/CP46, and the Transcan Grant JTC 2012 Cancer 12-054. HEBON thanks the Registration Teams of Dutch Cancer Registry (IKNL; S. Siesling, J. Verloop) and the Dutch Pathology database (PALGA; L. Overbeek) for their help in part of the data collection. HRBCP was supported by the Hong Kong Sanatorium and Hospital, Dr. Ellen Li Charitable Foundation, The Kerry Group Kuok Foundation, National Institute of Health 1R 03CA130065, and North California Cancer Center. Hungarian Breast and Ovarian Cancer Study (HUNBOCS) was supported by Hungarian Research Grants KTIA-OTKA CK-80745 and OTKA K-112228. ICO: Contract Grant Sponsor: Asociacion Espanola Contra el Cancer, Spanish Health Research Fund; Carlos III Health Institute; Catalan Health Institute and Autonomous Government of Catalonia. Contract Grant Numbers: ISCIIIRETIC RD06/0020/1051, RD12/0036/008, PI10/01422, PI10/00748, PI13/00285, PIE13/00022, 2009SGR290, and 2014SGR364. The IHCC was supported by Grant PBZ_KBN_122/P05/2004. The ILUH Group was supported by the Icelandic Association "Walking for Breast Cancer Research" and by the Landspitali University Hospital Research Fund. INHERIT: this work was supported by the Canadian Institutes of Health Research for the "CIHR Team in Familial Risks of Breast Cancer" Program: Grant No. CRN-87521 and the Ministry of Economic Development, Innovation and Export Trade: Grant No. PSR-SIIRI-701. The PERSPECTIVE Project was supported by the Government of Canada through Genome Canada and the Canadian Institutes of Health Research (Grant GPH-129344), the Ministere de l'Economie, Science et Innovation du Quebec through Genome Quebec, and the Quebec Breast Cancer Foundation. IOVHBOCS was supported by Ministero della Salute and "5x1000" Istituto Oncologico Veneto Grant. IPOBCS: this study was in part supported by Liga Portuguesa Contra o Cancro. kConFab was supported by a Grant from the National Breast Cancer Foundation, and previously by the National Health and Medical Research Council (NHMRC), the Queensland Cancer Fund, the Cancer Councils of New South Wales, Victoria, Tasmania, and South Australia, and the Cancer Foundation of Western Australia. KOHBRA was supported by a Grant from the National R&D Program for Cancer Control, Ministry for Health, Welfare and Family Affairs, Republic of Korea (1020350). MAYO was supported by NIH Grants CA116167, CA192393, and CA176785, an NCI Specialized Program of Research Excellence (SPORE) in Breast Cancer (CA116201), and a Grant from the Breast Cancer Research Foundation. MCGILL: Jewish General Hospital Weekend to End Breast Cancer, Quebec Ministry of Economic Development, Innovation and Export Trade. MODSQUAD was supported by MH CZ: DRO (MMCI, 00209805) and by the European Regional Development Fund and the State Budget of the Czech Republic (RECAMO, CZ.1.05/2.1.00/03.0101) to LF, and by Charles University in Prague Project UNCE204024 (MZ). MSKCC was supported by Grants from the Breast Cancer Research Foundation, the Robert and Kate Niehaus Clinical Cancer Genetics Initiative, and the Andrew Sabin Research Fund. NAROD: 1R01 CA149429-01. NCI: the research of Drs. MH Greene and PL Mai was supported by the Intramural Research Program of the US National Cancer Institute, NIH, and by Support Services Contracts NO2-CP-11019-50 and N02-CP-65504 with Westat, Inc., Rockville, MD. NICCC was supported by Clalit Health Services in Israel. Some of its activities were supported by the Israel Cancer Association and the Breast Cancer Research Foundation (BCRF), NY. NNPIO: this work has been supported by the Russian Federation for Basic Research (Grants 15-04-01744 and 16-54-00055). NRG Oncology: this study was supported by NRG Oncology Operations Grant Number U10 CA180868 as well as NRG SDMC Grant U10 CA180822, Gynecologic Oncology Group (GOG) Administrative Office and the GOG Tissue Bank (CA 27469), and the GOG Statistical and Data Center (CA 37517). Drs. Greene, Mai, and Savage were supported by Funding from the Intramural Research Program, NCI. OSUCCG was supported by the Ohio State University Comprehensive Cancer Center. PBCS: this work was supported by the Italian Association of Cancer Research (AIRC) [IG 2013 N.14477] and Tuscany Institute for Tumors (ITT) Grant 2014-2015-2016. SEABASS: Ministry of Science, Technology and Innovation, Ministry of Higher Education (UM.C/HlR/MOHE/06), and Cancer Research Initiatives Foundation. The SMC Team was in part sponsored by a Grant from the Israeli Cancer Association to the Israeli Consortium of Hereditary Breast Cancer. SWE-BRCA Collaborators were supported by the Swedish Cancer Society. UCHICAGO was supported by NCI Specialized Program of Research Excellence (SPORE) in Breast Cancer (CA125183), R01 CA142996, 1U01CA161032, and by the Ralph and Marion Falk Medical Research Trust, the Entertainment Industry Fund National Women's Cancer Research Alliance, and the Breast Cancer Research Foundation. OIO is an ACS Clinical Research Professor. UCLA: Jonsson Comprehensive Cancer Center Foundation; Breast Cancer Research Foundation. UCSF: UCSF Cancer Risk Program and Helen Diller Family Comprehensive Cancer Center. UKFOCR was supported by a Project Grant from CRUK to Paul Pharoah. UPENN: National Institutes of Health (NIH) (R01-CA102776 and R01-CA083855; Breast Cancer Research Foundation; Susan G. Komen Foundation for the Cure, Basser Research Center for BRCA. VFCTG: Victorian Cancer Agency, Cancer Australia, National Breast Cancer Foundation. WCP: Dr. Karlan was funded by the American Cancer Society Early Detection Professorship (SIOP-06-258-01-COUN) and the National Center for Advancing Translational Sciences (NCATS), Grant UL1TR000124. Sí

In most mammals, the Y chromosomal Sry gene initiates testis formation within the bipotential gonad, resulting in male development. SRY is a transcription factor and together with SF1 it directly up-regulates the expression of the pivotal sex-determining gene Sox9 via a 1.3-kb cis-regulatory element (TESCO) which contains an evolutionarily conserved region (ECR) of 180 bp. Remarkably, several rodent species appear to determine sex in the absence of Sry and a Y chromosome, including the mole voles Ellobius lutescens and Ellobius tancrei, whereas Ellobius fuscocapillus of the same genus retained Sry. The sex-determining mechanisms in the Sry-negative species remain elusive. We have cloned and sequenced 1.1 kb of E. lutescens TESCO which shares 75% sequence identity with mouse TESCO indicating that testicular Sox9 expression in E. lutescens might still be regulated via TESCO. We have also cloned and sequenced the ECRs of E. tancrei and E. fuscocapillus. While the three Ellobius ECRs are highly similar (94-97% sequence identity), they all display a 14-bp deletion (Δ14) removing a highly conserved SOX/TCF site. Introducing Δ14 into mouse TESCO increased both basal activity and SF1-mediated activation of TESCO in HEK293T cells. We propose a model whereby Δ14 may have triggered up-regulation of Sox9 in XX gonads leading to destabilization of the XY/XX sex-determining mechanism in Ellobius. E. lutescens/E. tancrei and E. fuscocapillus could have independently stabilized their sex determination mechanisms by Sry-independent and Sry-dependent approaches, respectively.

The branchio-oculo-facial syndrome (BOFS) is a rare disorder with approximately 50 sporadic and familial cases in the literature. We report on the clinical and molecular analyses of five additional patients with BOFS (two familial and three sporadic). DNA analysis of the TFAP2A gene associated with BOFS using DNA sequencing detected a mutation [c.763A>G (p.Arg255Gly)] in two unrelated patients. This mutation had been reported in another patient and indicates a probable mutational hotspot in the TFAP2A gene. We also detected three new mutations which are restricted to exons 4-6. These gene regions are almost free of any single nucleotide polymorphisms. An evolutionary sequence comparison showed a high degree of sequence conservation from humans to the honey bee (Apis mellifera) in exon 6 showing that this part of the protein is probably essential. Our study represents the second group of BOFS patients with molecular confirmation, expanding the phenotype and spectrum of mutations and limiting it to a restricted part of the gene.

The mole vole Ellobius lutescens is an interesting animal, not only concerning its sex determination mechanism without the Y-chromosomal Sry gene, that triggers sex determination in nearly all other mammalian species, but also regarding the karyotype with an odd number of chromosomes, being identical in male and female animals. The odd chromosome represents the X chromosome, and therefore, even males do not have a Y chromosome. We present an overview of a search for candidate genes of male sex determination in the mole vole Ellobius lutescens. A singular X raises questions about the need for X chromosome inactivation in female cells. We present preliminary data that support a hypothesis that the E. lutescensXist gene may be degenerated and thus non-functional.

The rodent Ellobius lutescens is an exceptional mammal which determines male sex constitutively without the SRY gene and, therefore, may serve as an animal model for human 46,XX female-to-male sex reversal. It was suggested that other factors of the network of sex-determining genes determine maleness in these animals. However, some sex-determining genes like SOX9 and SF1 have already been excluded by segregation analysis as primary sex-determining factors in E. lutescens. In this work, we have cloned and characterized two genes of the PIS (polled intersex syndrome) gene interval, which were reported as candidates in female-to-male sex reversal in hornless goats recently. The genes Foxl2 and Pisrt1 from that interval were identified in E. lutescens DNA and mapped to Chromosome 8. We have excluded linkage of Foxl2 and Pisrt1 loci with the sex of the animals. Hence, the involvement of this gene region in sex determination may be specific for goats and is not a general mechanism of XX sex reversal or XX male sex determination.

Branchio-oculo-facial syndrome (BOFS) is a rare entity described during the last century which has been recently linked to mutations of the gene encoding for the transcription factor named 'TFAPA2'. We report here a sporadic case of BOFS with a partial phenotype caused by a de novo mutation of this gene and discuss recent genetic findings.

Background SOX9 mutations cause the skeletal malformation syndrome campomelic dysplasia in combination with XY sex reversal. Studies in mice indicate that SOX9 acts as a testis-inducing transcription factor downstream of SRY , triggering Sertoli cell and testis differentiation. An SRY-dependent testis-specific enhancer for Sox9 has been identified only in mice. A previous study has implicated copy number variations (CNVs) of a 78 kb region 517–595 kb upstream of SOX9 in the aetiology of both 46,XY and 46,XX disorders of sex development (DSD). We wanted to better define this region for both disorders. Results By CNV analysis, we identified SOX9 upstream duplications in three cases of SRY -negative 46,XX DSD, which together with previously reported duplications define a 68 kb region, 516–584 kb upstream of SOX9 , designated XXSR (XX sex reversal region). More importantly, we identified heterozygous deletions in four families with SRY -positive 46,XY DSD without skeletal phenotype, which define a 32.5 kb interval 607.1–639.6 kb upstream of SOX9 , designated XY sex reversal region (XYSR). To localise the suspected testis-specific enhancer, XYSR subfragments were tested in cell transfection and transgenic experiments. While transgenic experiments remained inconclusive, a 1.9 kb SRY-responsive subfragment drove expression specifically in Sertoli-like cells. Conclusions Our results indicate that isolated 46,XY and 46,XX DSD can be assigned to two separate regulatory regions, XYSR and XXSR, far upstream of SOX9 . The 1.9 kb SRY-responsive subfragment from the XYSR might constitute the core of the Sertoli-cell enhancer of human SOX9 , representing the so far missing link in the genetic cascade of male sex determination.

Disorders of sex development (DSD) affect the development of chromosomal, gonadal and/or anatomical sex. We analyzed a patient with ambiguous genitalia aiming to correlate the genetic findings with the phenotype. Blood and tissue samples from a male patient with penoscrotal hypospadias were analyzed by immunohistochemistry, karyotyping and FISH. DNA was sequenced for the AR, SRY and DHH genes, and further 26 loci in different sex chromosomes were analyzed by MLPA. The gonosomal origin was evaluated by simple tandem repeat (STR) analysis and SNP array. Histopathology revealed a streak gonad, a fallopian tube and a rudimentary uterus, positive for placental alkaline phosphatase, cytokeratin-7 and c-kit, and negative for estrogen, androgen and progesterone receptors, alpha-inhibin, alpha-1-fetoprotein, ��-hCG, and oct-4. Karyotyping showed a 45,X/46,XY mosaicism, yet FISH showed both 46,XX/46,XY mosaicism (gonad and urethral plate), 46,XX (uterus and tube) and 46,XY karyotypes (rudimentary testicular tissue). DNA sequencing revealed intact sequences in SOX9, WNT4, NR0B1, NR5A1, CYP21A2, SRY, AR, and DHH. STR analysis showed only one maternal allele for all X chromosome markers (uniparental isodisomy, UPD), with a weaker SRY signal and a 4:1 ratio in the X:Y signal. Our findings suggest that the observed complex DSD phenotype is the result of somatic gonosomal mosaicism and UPD despite a normal blood karyotype. The presence of UPD warrants adequate genetic counseling for the family and frequent, lifelong, preventive follow-up controls in the patient. �� In Copyright http://rightsstatements.org/vocab/InC/1.0/, publishedVersion

Investigations in mice suggest that the Y-chromosomal genes affect certain behaviors. Here, we studied whether a part of the Y chromosome, the Sxr locus, has an effect on induction of motivation for parental care (pup retrieval) or of parental aggression towards pups (infanticide). XX females, XX males with the Sxr locus on the X chromosome, and XY males of the C57BL/6J strain were tested. The induced pup retrieval or infanticide behaviors were genotype-dependent. XX mice always retrieved pups and never were infanticidal. On the first test, significantly more XY males (38%) than XX males (17%) were infanticidal. When the same animals were tested for a second time, all except one of the XX males retrieved pups. Overall, motivation for parental care was highest in XX females, followed by XX males, and lowest in XY mice. On the other hand, the incidence of infanticide was highest in XY males, lower in XX males, and absent in XX females. We conclude that the Sxr locus of the Y chromosome, when operating in a XX background, partially erases but does not fully defeminize motivation for pup retrieval. Further, it induces infanticide to a level higher than that of XX females but significantly lower than that of normal males (XY). Hence, we suggest that genes outside the sex-determining region of the Y chromosome and/or genes on autosomes are necessary for manifestation of full male-type parental behavior.

Mammalian sex determination and gonad differentiation are the result of a complex interaction of fine-tuned spatial and temporal gene expression with threshold levels of individual genes. The male pathway is initiated by SRY. Some exceptional mammals determine male sex without the SRY gene and even without a Y chromosome. Ellobius lutescens in this report is one example of this “weird” species. We provide key data on the genomic level that there are no coarse differences in the genomes of male and female animals by comparative genomic hybridization. On the gene level we studied the gene Nr5a1 for the orphan nuclear receptor, steroidogenic factor SF-1, a central constituent for gonad differentiation and adrenal gland development. The Ellobius lutescens Nr5a1 gene was mapped to the proximal short arm of chromosome 2 by fluorescence in situ hybridization. In addition, we provide evidence by linkage analysis in two E. lutescens pedigrees that Nr5a1 is not the key male sex-determining gene in Ellobius lutescens.

1526 Background: 24% of familial breast cancer (BC) and/or ovarian cancer (OC) cases analyzed within the framework of the German Consortium for Hereditary Breast and Ovarian Cancer (GC-HBOC) are due to pathogenic mutations in the BRCA1 or BRCA2 genes. The population-specific mutation prevalence of non- BRCA1/2 genes associated with familial BC and/or OC is largely unknown and was determined in a large German cohort. Methods: Here, we present next-generation sequencing (NGS) data established from TruRisk (GC-HBOC-designed) or TruSight cancer gene panels. A cohort of 6,507 BRCA1/2-negative index cases fulfilling the inclusion criteria of the GC-HBOC for germline testing was analyzed. Illumina sequencing platforms were used and data analysis was carried out at each individual center using different analysis pipelines. Analysis of copy number variations (CNV) was not included in the present data evaluation. Results: By focusing on 8 confirmed BC/OC risk genes ( ATM, CDH1, CHEK2, NBN, PALB2, RAD51C, RAD51D, TP53), the 6,507 cancer patients revealed 165 different deleterious variants in 378 unrelated mutation carriers (5.8%). We found a high prevalence of CHEK2 (n = 150, 2.3%), ATM (n = 89, 1.4% ), and PALB2 (n = 72, 1.1%) mutations while RAD51C (n = 21, 0.3%), TP53 (n = 16, 0.2%), NBN (n = 15, 0.2%), CDH1 (n = 10, 0.2%), and RAD51D (n = 5, 0.1%) were less frequently mutated. Conclusions: The high frequency of pathologic mutations in the genes ATM, CDH1, CHEK2, NBN, PALB2, RAD51C, RAD51D, and TP53, together accounting for almost 6% of familial BC/OC risk, highlights the importance of these genes to be included in BC/OC routine diagnostics. The relevance of these mutations in a clinical setting for early detection of breast and ovarian cancer needs to be established.

A new recurrent point mutation in the COL1A2 gene was found in a patient with type III osteogenesis imperfecta (OI). A G-to-T transversion in nucleotide position 1121 leads to an amino acid substitution Gly238Cys. This is the first report on the most N-terminal cysteine substitution in COL1A2 reported so far. Until now, at this position, only serine substitutions were observed five times in unrelated patients showing a highly variable expression of OI. It is obvious that endogenic and/or exogenic modifiers are involved in this classical autosomal dominant (or rarely recessive) mendelian disorder. An apparent preferential substitution by cysteine and serine residues is discussed with reference to post-transcriptional or post-translational collagen assembly control.

In mammals the initiation of testis determination usually depends on the Y-chromosomal gene SRY. A few species, however, escape from this rule with a testis determination that is independent of SRY. The mole vole Ellobius lutescens is one of these species. It is not known how testis determination is initiated in this species but it has been suggested that a gene from the sex determination cascade usually acting downstream of SRY is mutated and has taken over the testis-determining function. At present SOX9 is the only candidate gene for which a testis-determining function in the absence of SRY has been observed. To test the hypothesis that testis differentiation in E. lutescens is initiated by SOX9, segregation analysis of SOX9 alleles was performed in an E. lutescens family. As there is no marker data available in this species we screened both Ellobius SOX9 introns for polymorphisms suitable for segregation studies. A biallelic polymorphism was found in the second intron of the SOX9 gene and analysis of this marker in the Ellobius family revealed an inheritance pattern completely independent of the sex of the animals. Thus, SOX9 can be excluded from being the testis-determining factor in E. lutescens. These results provide evidence for another possibly yet unknown gene besides SRY and SOX9 able to exert testis-determining function.

Glossophaga soricina is a flower-visiting bat which lives in the neotropics. The diploid chromosome number is 2n = 32 with a fundamental number of autosomal arms, FN, of 60. G. soricina belongs to the Microchiroptera which have a lower diploid DNA content and a higher AT composition in their DNA compared with other mammals. By ZOO-FISH analysis with human chromosome-specific DNA probes, the human autosomes were found conserved in 41 segments. This is an arrangement similar to other mammals which have been analyzed. Several chromosomal associations already known from ZOO-FISH studies in other species were also present in G. soricina.

The unusual karyotype of Ellobius lutescens (2n = 17,X in males and females) has attracted permanent interest and prompted a series of hypotheses on sex determination in this species since its first description by Matthey (1953). The developing knowledge about the sex chromosomes and sex determination as well as the availability of new cytogenetic and molecular genetic techniques prompted studies to test the compatibility between current hypotheses and new findings and rendered modifications of the hypotheses necessary. After a long period dominated by the question what the sex chromosome constitution of this species might be and where the testis determining factor could be located, the presence of Sry had been eventually excluded and sex determination attributed to a hypothetical mutated gene acting downstream of Sry. An X-chromosomal or autosomal location of this gene can be assessed by cosegregation of sex with X-chromosome markers. Some preliminary results concerning X-chromosome dinucleotide repeat markers are reported. However, these markers were homomorphic in Ellobius lutescens. We now report evidence that Zfy is also missing in Ellobius lutescens and E. tancrei (males and females XX), a finding from which we conclude that the entire Y chromosome has been lost from these species. Perspectives concerning future studies are discussed.

The GGGGCC-hexanucleotide repeat expansion in C9orf72 is the most common genetic cause of familial amyotrophic lateral sclerosis and frontotemporal dementia. This study determined the frequency of C9orf72 repeat expansions in different motor neuron diseases (amyotrophic lateral sclerosis (ALS), motor neuron diseases affecting primarily the first or the second motor neuron and hereditary spastic paraplegia). Whereas most studies on C9orf72 repeat expansions published so far rely on a polymerase chain reaction-based screening, we applied both polymerase chain reaction-based techniques and Southern blotting. Furthermore, we determined the sensitivity and specificity of Southern blotting of the C9orf72 hexanucleotide repeat in DNA derived from lymphoblastoid cell lines. C9orf72 repeat expansions were found in 27.1% out of 166 familial ALS patients, only once in 68 sporadic ALS patients, and not in 61 hereditary spastic paraplegia patients or 52 patients with motor neuron diseases affecting clinically primarily either the first or the second motor neuron. We found hints for a correlation between C9orf72 repeat length and the age of onset. Somatic instability of the C9orf72 repeat was observed in lymphoblastoid cell lines compared with DNA derived from whole blood from the same patient and therefore caution is warranted for repeat length determination in immortalized cell lines.

Duplications in Xp including the DSS (dosage sensitive sex reversal) region cause male to female sex reversal. We investigated two patients from families with Xp duplications. The first case was one of two sisters with karyotype 46,XY, der(22), t(X;22)(p11.3;p11)mat and unambiguous female genitalia. The living sister was developmentally retarded, and showed multiple dysmorphic features and an acrocallosal syndrome. The second case was a boy with a maternally inherited direct duplication of Xp21.3-pter with the breakpoint close to the DSS locus. He had multiple abnormalities and micropenis, but otherwise unambiguous male genitalia. We performed quantitative Southern blot analysis with probes from Xp22.13 to p21.2 to define the duplicated region. Clinical, cytogenetic, and molecular data from both patients were compared with those of previously reported related cases. A comparison of the extragenital symptoms revealed no differences between patients with or without sex reversal. In both cases, the symptoms were non-specific. Among 22 patients with a duplication in Xp, nine had unambiguous female genitalia and a well-documented duplication of the DSS region. Two patients with duplication of DSS showed ambiguous external genitalia. From these data, we conclude that induction of testicular tissue may start in these patients, but that the type of genitalia depends on the degree of subsequent degeneration by a gene in DSS.

We report on 12- and 14-year-old sisters with a 46,XY chromosome constitution, normal female external genitalia, and absence of gonadal tissue. Except for omphalocele, right renal agenesis and malrotation of the colon in the elder sister, the internal organs were normal. Both were mentally retarded, of short stature, and had extremely retarded bone age. In addition, they had an almost identical pattern of minor anomalies: peculiar face, hypodontia, short neck, inverted nipples, thoracolumbar scoliosis, “dysplastic” hips, partial clino-/syndactyly of toes. The occurrence of a basically similar set of malformations in two sisters and the first cousin consanguinity of the parents suggests autosomal recessive inheritance. The conserved region of the SRY gene ([high mobility group] HMG box) was sequenced in the elder sib and was normal. No consistent malformations are observed at present in agonadal patients. This supports the idea that several autosomal genes have the potential of influencing the sequence of events of sex determination. © 1995 Wiley-Liss, Inc.

We report the mRNA and protein expression levels of human biglycan (BGN) in patients with different numbers of sex chromosomes. BGN maps to the distal long arm of the X chromosome, band Xq28, near the second pseudoautosomal region. BGN expression levels are reduced in 45,X Turner patients and increased in patients with additional sex chromosomes. This is suggestive of a pseudoautosomal gene or a gene that escapes X inactivation and that has an active Y chromosomal copy. However, we also provide evidence from hybrid cell lines that BGN is subject to X inactivation and that there is no homolog on the Y chromosome. This evidence excludes an escape from X inactivation. Moreover, additional Y chromosomes increase BGN expression levels, despite the absence of a Y chromosomal BGN gene. Therefore, another explanation has to be invoked. The "pseudoautosomal expression" of BGN may be attributed to a gene or genes that escape X inactivation and that regulate the transcriptional activity of BGN. This is the first report concerning an X chromosomal gene that does not show the conventional correlation between gene dosage and expression rate known from other X chromosomal genes.

A critical review of the literature disclosed 44 cases with a 46,X,Xq- karyotype without apparent mosaicism. Of these, 17 were of normal height (compared to the respective population), 11 had a height of over 1 SD below the mean, and 16 had a height of over 2 SD below the mean with breakpoints between Xq13 and Xq25. Since patients of normal height occurred with breakpoints as proximal as Xq13 we conclude that there is no major "growth gene" on Xq distal to q13. The most likely explanation for the variable phenotypic effect of Xq- is to assume that growth gene(s) in Xp or proximal Xq are inactivated on such a chromosome with some variability similar to the variable spreading of X inactivation seen in some X-autosome translocations.

Branchio-oculo-facial syndrome represents a craniofacial disorder in which affected patients may develop a wide range of distinctive features that include cleft lip and/or palate, cervical aplastic skin defect, malformed pinna, and ocular anomalies. This study reports four new cases confirmed by the identification of mutations in the TFAP2A gene and describes in detail the findings in the craniofacial region. The four cases included two familial and two sporadic, and three have been followed since the birth. Two out of the four cases showed atypical features. One patient presented brainstem immaturity with dysregulation of sympathetic and parasympathetic systems, which have so far not been described in the literature and were associated with anxiety, panic attacks, and tiredness. Another patient had as an additional feature a hypoplastic thumb with distal implantation.

To elucidate the function of the FMR1 gene, we applied RNA in situ hybridization to cryosections of mice from different developmental stages. The murine Fmr-1 was found transcribed in a ubiquitous manner with an expression pattern similar to glyceraldehyd phosphate dehydrogenase, Gapdh, which was used as a control gene. A significant difference in the Fmr-1 expression pattern, however, was markedly enhanced expression specifically confined to the testis and the fetal ovary. In the immature and mature testis an elevated level of Fmr-1 expression is found in type A1 spermatogonia. Expression in the testis is observed in fetal life, reaches the highest level in the immature testis, and declines early in adult life. In the mature ovary no specific Fmr-1 expression signal was found but enhanced levels were seen in the fetal ovary. At this developmental stage proliferation of oogonia takes place. It is suggested that FMR1 serves a special function during germ cell proliferation in males and females. These findings are discussed in the light of the current observation that fragile X patients produce only sperm with a premutation sized allele. Two hypotheses are put forward: (1) In males lack of FMR1 function results in a premeiotic defect preventing spermatogonia with a full mutation to reach meiosis. A fragile X mutation can be passed on to offsprings only as a premutation (selection hypothesis). (2) Transition of a premutation allele to full mutation occurs in a postzygotic stage after separation of the germ line and is restricted to soma cells (restriction hypothesis). Expression of FMR1 in proliferating germ cells is in line with both hypothesis.

Using cross-species chromosome painting, we have carried out a comprehensive comparison of the karyotypes of two Ellobius species with unusual sex determination systems: the Transcaucasian mole vole, Ellobius lutescens (2n = 17, X in both sexes), and the northern mole vole, Ellobius talpinus (2n = 54, XX in both sexes). Both Ellobius species have highly rearranged karyotypes. The chromosomal paints from the field vole (Microtus agrestis) detected, in total, 34 and 32 homologous autosomal regions in E. lutescens and E. talpinus karyotypes, respectively. No difference in hybridization pattern of the X paint (as well as Y paint) probes on male and female chromosomes was discovered. The set of golden hamster (Mesocricetus auratus) chromosomal painting probes revealed 44 and 43 homologous autosomal regions in E. lutescens and E. talpinus karyotypes, respectively. A comparative chromosome map was established based on the results of cross-species chromosome painting and a hypothetical ancestral Ellobius karyotype was reconstructed. A considerable number of rearrangements were detected; 31 and 7 fusion/fission rearrangements differentiated the karyotypes of E. lutescens and E. talpinus from the ancestral Ellobius karyotype. It seems that inversions have played a minor role in the genome evolution of these Ellobius species.

In amyotrophic lateral sclerosis (ALS) patients with known genetic cause, mutations in chromosome 9 open reading frame 72 (C9orf72) and superoxide dismutase 1 (SOD1) account for most familial and late-onset sporadic cases, whereas mutations in fused in sarcoma (FUS) can be identified in just around 5% of familial and 1% of overall sporadic cases. There are only few reports on de novo FUS mutations in juvenile ALS patients. To date, no systematic evaluation on the frequency of de novo FUS mutations in early-onset ALS patients has been conducted. Here, we screened a cohort of 14 early-onset sporadic ALS patients (onset age

The complex mechanisms are responsible for male sex determination and differentiation. The steps of formation of the testes are dependent on a series of Y-linked, X-linked and autosomal genes actions and interactions. After formation of testes the gonads secrete hormones, which are essential for the formation of the male genitalia. Hormones are transcription regulators, which function by specific receptors. Ambiguous genitalia are result of disruption of genetic interaction. This review describes the mechanisms, which lead to differentiation of male sex and ways by which the determination and differentiation may be interrupted by naturally occurring mutations, causing different syndromes and diseases.

Constitutional missense mutations in the WT1 gene are usually associated with Denys-Drash syndrome. This rare syndrome is characterized by a rapid progressive nephropathy, male pseudohermaphroditism, and an increased risk for Wilms tumor. We report on a patient with incomplete Denys-Drash syndrome, which was evident by the clinical data and proved by molecular genetics methods. The patient has the mutation p.R394W in the WT1 gene and clinical symptoms of Denys-Drash syndrome.

Investigations in mice suggest that the Y-chromosomal genes affect certain behaviors. Here, we studied whether a part of the Y chromosome, the Sxr locus, has an effect on induction of motivation for parental care (pup retrieval) or of parental aggression towards pups (infanticide). XX females, XX males with the Sxr locus on the X chromosome, and XY males of the C57BL/6J strain were tested. The induced pup retrieval or infanticide behaviors were genotype-dependent. XX mice always retrieved pups and never were infanticidal. On the first test, significantly more XY males (38%) than XX males (17%) were infanticidal. When the same animals were tested for a second time, all except one of the XX males retrieved pups. Overall, motivation for parental care was highest in XX females, followed by XX males, and lowest in XY mice. On the other hand, the incidence of infanticide was highest in XY males, lower in XX males, and absent in XX females. We conclude that the Sxr locus of the Y chromosome, when operating in a XX background, partially erases but does not fully defeminize motivation for pup retrieval. Further, it induces infanticide to a level higher than that of XX females but significantly lower than that of normal males (XY). Hence, we suggest that genes outside the sex-determining region of the Y chromosome and/or genes on autosomes are necessary for manifestation of full male-type parental behavior.

Branchio-oculo-facial syndrome (BOF, MIM 1136201) is a rare autosomal dominant disorder. The symptoms of this disorder include bilateral postauricular cervical branchial sinus defects with haemangiomatous, scarred skin, cleft lip with or without cleft palate, pseudocleft of the upper lip, nasolacrimal duct obstruction, low set ears with posterior rotation, a malformed, asymmetrical nose with a broad bridge and flattened tip, and, occasionally, prematurely grey hair. Father to son transmission of this disorder has been observed,2 which indicate autosomal dominant inheritance. Another disorder with hearing loss resulting from bilateral branchial cleft fistulas is branchio-oto-renal syndrome (BOR, MIM 113650). Common features of both syndrome are summarised in table 1. Some characteristics of both BOR and BOF syndromes have been reported in a father (BOF) and his son (BOR), but the constant features of BOF syndrome were not observed in either of them. This observation led to the conclusion that BOF and BOR might be allelic variants of the same gene.3 It was suggested that, in both syndromes, penetrance and expression could be variable, and it was concluded that BOF and BOR syndromes are the variable results of mutations in the same autosomal gene.3 However, it was pointed out later that both subjects in fact should be considered as BOF syndrome rather than BOF and BOR syndrome, and that these syndromes are distinct entities and may not be allelic.4 Another related disorder is branchio-otic syndrome (BO, MIM 602588), which comprises branchial fistulas, preauricular pits, and hearing impairment, but lacks renal anomalies (table 1). View this table: Table 1 Branchiogenic disorders The first candidate gene for BOR has been mapped. This gene, EYA1 (“eyes absent-like”, a human homologue of the Drosophila eyes absent gene), was found by positional cloning5 and maps to chromosome 8q13.3. Mutations in EYA1 have been described,6–8 which made …

The human aggrecan gene (AGC1) has been localized to 15q25--q26.2 by in situ hybridization. Although no genetic diseases of connective tissue map to this location, the malignant melanoma-associated surface antigen mel-CSPG is located here; mel-CSPG is a chondroitin sulfate proteoglycan. This raises the possibility that AGC1 and mel-CSPG may be the same gene.

Editor—The branchio-oculo-facial syndrome (BOFS) is characterised by a branchial cleft sinus or linear skin lesion behind the ear, lacrimal duct obstruction, colobomata of the iris/retina, hypertrophy of the lateral pillars of the philtrum (“pseudocleft”), an asymmetrical nose with a broad tip, and auricular and lip pits. Premature greying of the hair is also observed.1 Inheritance is autosomal dominant (OMIM 113620).2 Several anomalies common to both BOF and BOR (branchio-oto-renal) syndromes have been reported.3 McCool and Weaver4 reported three cases with BOF and unilateral renal agenesis. This anomaly is not frequent in BOFS but is characteristic for patients with BOR, and hence a contiguous gene syndrome or the presence of different mutations within a single gene have been suggested.4 Recently, the BOR gene was identified by positional cloning on chromosome 8q13.3 and mapped between markers D8S1060 and D8S1807.5 The gene was named “eyes absent-like 1” ( EYA1 ), the human homologue of the Drosophila eyes absent gene. It has been postulated that the EYA1 gene and two other EYA related genes ( EYA2 on chromosome 20q13.1 and EYA3 on 1p36) play a role in development.5 Based on the largest published family with BOFS6 and in order to find a candidate gene for BOFS, we studied four flanking markers in the BOR chromosome region ( EYA1 gene)7 as well as six markers flanking the EYA2 gene,8 four markers at the EYA3 gene,9 and four markers close to the EYA4 gene, which has recently been mapped to 6q23.10 The family studied here was described in detail by Lin et al …

Alleles of the CAG and the GGC repeat in the first exon of the human androgen receptor (AR) gene have been shown to be associated with the risk of (advanced) prostate cancer. These studies had been carried out in the United States. We have analysed these polymorphisms in a French-German collection of 105 controls, 132 sporadic cases, and a sample of prostate cancer families comprising 85 affected and 46 not affected family members. The allele distributions were very similar in all four groups and chi square statistics on contingency tables did not detect any significant differences. The relative risk (odds ratio, OR) were calculated using logistic regression and did not reach significance despite sufficient numbers of patients and controls. Typical results were OR = 1.007; 95% Confidence Interval (CI) 0.97-1.1, P = 0.87 for CAG as continuous variable and OR = 1.2 (95% CI 0.7-2.0), P = 0.47 for CAG classes22 and= 22 repeats. Similar results were obtained for subgroups defined by age or Gleason score. We conclude that these polymorphisms can not be used as predictive parameters for prostate cancer in the French or German population.

Amniocentesis (AC) is by far the most often used invasive prenatal diagnostic procedure. Amniotic fluid cells were first used for prenatal diagnosis by Fuchs and Philipp (1963) for sex chromatin determination in a pregnancy at risk for an X-linked disease. After successful establishing of amniotic fluid cell culture techniques by Steele and Breg (1966), 2 years later the first prenatal diagnoses of a chromosome aberration ie trisomy 21 (Valenti et al. 1968), and of a metabolic disorder ie galactosaemia (Nadler 1968) were reported.

The transcriptional regulation of human biglycan expression under normal and pathological conditions was studied. The 5'-flanking regions of the human and mouse genes were isolated and analyzed; the two promoter regions share 81% identity. Both promoters are without a TATA and CAT box and contain multiple Sp1 sites. Human dermal fibroblasts were transiently transfected with progressive deletional human biglycan 5'-flanking DNA-CAT constructs, and a significant variation in activity among the individual constructs was found. A small deletion in several cases caused a more than 2-fold increase or decrease in promoter activity, thereby mapping the target sites for repressors or activators. Human biglycan expression is reduced in females with Ullrich-Turner syndrome (45,X) and increased in individuals with supernumerary sex chromosomes, and it has been speculated that biglycan plays a role in the short stature phenotype of Turner syndrome. Analysis of the transcriptional regulation of biglycan in individuals with sex chromosome anomalies showed that a -262 to -218 region of the biglycan promoter was differentially regulated. This region was extensively analyzed by DNAse footprinting and electrophoretic mobility shift assays, and a putative binding site for the transcription factor c-Krox was discovered. The binding of c-Krox to a site located at approximately -248 to -230 in the human biglycan promoter was confirmed by using extracts from COS cells expressing recombinant human c-Krox. The expression of c-Krox in bone was then examined by reverse-transcribed polymerase chain reaction and Northern blotting analysis; an approximately 3.4 kb transcript was detected in primary osteoblastic cells, in MG-63 cells, and in human bone marrow stromal cells. This is the first detection of c-Krox in bone cells, and it suggests that c-Krox, like another member of the Krox family, Krox-20, might play a regulatory role in bone.

We report on a 19-week-old fetus with a 46,XX karyotype, normal female external genitalia, complete gonadal agenesis, large encephalocele, spina bifida, and omphalocele. We postulate a new syndrome. Hitherto no consistent malformation patterns have been observed in agonadism patients. True agonadism, including even the unusual finding of an XX gonosomal status, is obviously not as rare as suggested.

Ullrich-Turner syndrome (UTS) is frequently associated with monosomy X but may also occur with structural aberrations of the X and the Y chromosomes. It has been hypothesized that the ribosomal protein genes RPS4X and RPS4Y play a critical role in the prevention of UTS. Individual patients with a 46,X,i(Xq) karyotype cannot be differentiated phenotypically from 45,X UTS patients and carry three gene copies of RPS4X. Since haploinsufficiency of one or several gene(s) is thought to cause the UTS phenotype, direct assessment of RPS4X expression levels in these patients should establish whether RPS4X is involved in UTS. We have investigated fibroblasts of four 46,X,i(Xq) UTS patients with typical symptoms and a non-mosaic chromosome complement, and have found significantly increased RPS4X mRNA levels in all patients. Based on our results, we conclude that haploinsufficiency of RPS4X is not the cause of UTS.

DNA in situ hybridization with human chromosome specific DNA libraries was applied to compare the karyotypes of humans (Homo sapiens, 2n = 46) and cats (Felis catus, 2n = 38). For the autosomes alone, 30 segments of conserved synteny were revealed. The arrangement of these segments in the feline karyotype differs by only seven single chromosome breaks and one intrachromosomal inversion from their arrangement in humans. Comparison of these data with those recently obtained for pig and those available from conventional gene mapping studies in mice and cattle has allowed us to develop a model of karyotype evolution in mammals. The cat and human karyotypes, with 36 and 44 autosomes respectively, were found to be very similar to a putative ancient mammalian founder karyotype. It would appear that during evolution to the human karyotype the status quo has been conserved for at least some 100-120 million years. There has been no need to alter the well-balanced gene arrangement of the mammalian founder karyotype.

The Y chromosomal gene Sry encodes a putative transcription factor which appears to serve as a master switch initiating testicular development. Here we show that this gene is transcribed in hypothalamus, midbrain, and testis of adult male but not adult female mice. In contrast to its circular transcripts in adult testis, those in brain are linear and may be translated. We propose that Sry exerts a role in the regulation of sex differentiation of the mammalian nervous system.

The Polled mutation of the goat is inherited as an autosomal dominant trait. Homozygotes with a 60, XX karyotype develop into intersexes. We looked for the presence of Y-chromosomal sequences (Zfy and Sry) in a male pseudohermaphrodite polled goat by Southern blotting and PCR analysis. Molecular analysis revealed that this XX goat had no Sry sequence. It showed identical hybridization patterns, using the human SRY and ZFY probes at low stringency, with the normal XX female goat, whereas an XY male revealed prominent Sry and Zfy signals. Identical results were obtained from PCR analysis with the caprine Sry primers. The possible role of an autosomal recessive gene in the induction of testes and maleness is discussed.

All of the protein-encoding exons and the 3' flanking region of the human decorin gene have been cloned and partially sequenced. The locations of the intron-exon junctions within the coding portion of the gene were identical to those found for the homologous human gene, biglycan. The sizes of the introns in the decorin gene, however, were substantially larger than those of the same introns of the biglycan gene. Portions of introns 1, 2, and 3 as well as exon 1 were not found during our extensive screening process. The 5' end of intron 2 was found to have an AG-rich region followed immediately by a CT-rich region. Furthermore, the 5' end of intron 3 was very rich in thymidine, whereas the 3' end of intron 7 was rich in adenosine. Several cDNA clones constructed from cultured human bone cell mRNA were found to contain a different sequence at the 5' end compared to that previously published for mRNA from a human embryonic fibroblast cell line. We were also unable to find the alternate 3' flanking region of the previously published cDNA sequence. We have mapped the human decorin gene by in situ methods to chromosome 12q21.3.