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In the present study we analysed the possible effect of age, sex and smoking on the mean values of micronucleus (MN) and sister chromatid exchange (SCE) frequencies on peripheral blood obtained from 38 subjects ranging in age from 16 to 63 years and 16 centenarians. The mean number of binucleated cells with micronuclei varied in function of age and sex (as demonstrated by the analysis of covariance (F=13.13; P<0.001), particularly evident was the increment observed in women with increasing age (interaction age/sex: F=5.53; P<0.05). Smoking habits had no effects on MN frequency (F=0.36; P>0.05). Sex (F=4.18; P<0.05) and smoking habits (F=14.64; P<0.001) influenced significantly SCE per cell frequencies, but age had no effects on them (F=2.45; P>0.05). The age-associated increase of sex chromosome loss was studied using fluorescence in situ hybridisation (FISH) on interphase nuclei. The loss of Y signals was observed in approximately 10% of interphase cells from the centenarians males, that is six times more often than in the younger control men (approximately 1.6%). The frequency of X signal loss (approximately 1.7%) in young women was similar to that observed in male controls of the same age but the incidence of the X chromosome aneuploidy in centenarian females was appreciably higher (approximately 22%) than that found for the Y chromosome in males. These results were correlated with the data on MN formation and a positive correlation between the percentage of aneuploid cells (FISH) and MN values was observed (r=0.50; P<0.05).

Males with a 47,XYY karyotype generally have chromosomally normal children, despite the high theoretical risk of aneuploidy. Studies of sperm karyotypes or FISH analysis of sperm have demonstrated that the majority of sperm are chromosomally normal in 47,XYY men. There have been a number of meiotic studies of XYY males attempting to determine whether the additional Y chromosome is eliminated during spermatogenesis, with conflicting results regarding the pairing of the sex chromosomes and the presence of an additional Y. We analyzed recombination in the pseudoautosomal region of the XY bivalent to determine whether this is perturbed in a 47,XYY male. A recombination frequency similar to normal 46,XY men would indicate normal pairing within the XY bivalent, whereas a significantly altered frequency would suggest other types of pairing such as a YY bivalent or an XYY trivalent. Two DNA markers, STS/STS pseudogene and DXYS15, were typed in sperm from a heterozygous 47,XYY male. Individual sperm (23,X or Y) were isolated into PCR tubes using a FACStarPlus flow cytometer. Hemi-nested PCR analysis of the two DNA markers was performed to determine the frequency of recombination. A total of 108 sperm was typed with a 38% recombination frequency between the two DNA markers. This is very similar to the frequency of 38.3% that we have observed in 329 sperm from a normal 46,XY male. Thus our results suggest that XY pairing and recombination occur normally in this 47,XYY male. This could occur by the production of an XY bivalent and Y univalent (which is then lost in most cells) or by loss of the additional Y chromosome in some primitive germ cells or spermatogonia and a proliferative advantage of the normal XY cells.

We have used polymorphisms within the Xp/Yp pseudoautosomal region (PAR 1) to determine the frequency and location of recombination in 80 paternally derived 47, XXY males. Of 64 informative results, there were 10 single cross-overs, one double cross-over and 53 without a cross-over. Therefore 2/3 of 47, XXY males of paternal origin result from meiosis in which the X and Y chromosomes fail to recombine. This failure was not associated with the presence of an increase in recombination in the smaller Xq/Yq pseudoautosomal region (PAR 2) or with the presence of microdeletions within PAR 1.

49,XXXXY syndrome is a very rare condition that is associated with a considerable more severe phenotype than classic 47,XXY Klinefelter syndrome. We present a patient with 49,XXXXY syndrome, who was first presented to an endocrinological unit at the age of 12.5 years with prepubertal genitalia. He was then lost from follow-up and showed clear clinical and biochemical signs of hypergonadotropic hypogonadism when presenting again at the age of 16 years. The patient was started on testosterone replacement therapy. This case is reported to underline the need for thorough endocrinological follow-up examinations in males with X polysomies., (Copyright 2000 S. Karger AG, Basel)

The sex chromosomal equipment in 26,675 sperm of 47,XYY males was analyzed. A total of 5.78% of the nuclei exhibited sex chromosome hyperhaploidy. Six studies have analyzed the sperm of 10 XYY patients and, although these studies indicated some degree of elimination of the extra Y chromosome during spermatogenesis, a certain percentage of XYY germinal cells may also be able to achieve meiosis and produce sperm with gonosomal disomies. All these studies show an increased incidence of gonosomal aneuploidies in sperm, but there are significant discrepancies concerning the extent of these abnormalities. The global frequencies of sperm with an abnormal number of sex chromosomes ranged from 0.578 to 13.91%, depending on the patients. There are several explanations for these discrepancies: differences attributed to fluorescence in situ hybridization methodology, the use of dual or multicolor FISH, recruitment, interindividual variations, and intraindividual variations. This study reports an additional series obtained from another XYY individual and compares and discusses the data on gonosomal hyperhaploidies in sperm of 47 XYY males using in situ hybridization analyses.

The testicular histology and the presence or absence of 32 Y DNA loci was investigated, with a focus on the long arm of Y chromosome (Yq) interval 6, by means of a polymerase chain reaction strategy in 2 XX males. Seminiferous tubules lined by only Sertoli cells and a slight thickening of tubular walls were observed. The men showed an absence of 32 Y DNA loci. These facts suggest that severe spermatogenic impairment is caused by deletions of Yq interval 6 in XX males.

Kennedy's syndrome is an inherited disease which was probably first described 100 years ago. Although rare, a recent report suggests that the prevalence may show considerable regional differences. A review of 30 different names of the disease is given. Originally, the disorder was regarded as a spinal and bulbar muscular atrophy but it is now obvious that there is severe axonal degeneration, also of the sensory fibres with the pattern of a central-peripheral distal axonal neuropathy. This was also present in the two recognized cases presented here. The sensory symptoms develop slowly and it is suggested that a peripheral sprouting compensates for the loss not only of motor, but also sensory fibres. It is important to distinguish the disease from motor neuron diseases since the progression is slow and the expected life span is normal. The clinical presentation with facial palsy and perioral contraction-fasciculations is pathognomonic. However, demonstration of increased (CAG)n repeat size in the androgen receptor gene is diagnostic. A normal (CAG)n repeat size excludes the diagnosis, since the abnormal expansion is the only mutation associated with the disease. Other types of mutations in the androgen receptor gene lead to a different clinical presentation, testicular feminization.

A 22-week stillborn fetus with 47,XXX karyotype had lower mesodermal defects consisting of irregular fusion of the sacral vertebrae, anal agenesis, multicystic dysplasia of a horseshoe kidney, a single umbilical artery, dysplastic ovaries, and uterine hypoplasia. This case provides additional evidence for an association between trisomy X and genitourinary defects including lower mesodermal defects sequence.

A case of microphthalmia with Xp microdeletion is reported. The patient was a boy who showed bilateral microphthalmia with corneal opacities, hypospadias without evidence of hypogonadism, and a conduction disturbance of the heart (Wenckebach conduction). No skin lesion was discerned. High-resolution chromosome analysis revealed the karyotype of 46,X,del(X)(p22). The phenotype was considered to be microphthalmia with linear skin defects (MLS) syndrome without skin lesions. Polymerase chain reaction and fluorescence in-situ hybridization analyses revealed that the chromosome aberration resulted from an X;Y translocation: the presence of pseudoautosomal boundary Y and the sex-determining region of Y was confirmed, while Xp deletion involving the region distal to DXS1129 was ascertained. Thus the chromosome designation using the ISCN 1995 nomenclature is 46,X,der(X),t(X;Y)(p22.13;q11.2). Despite the absence of skin lesions, the Xp deletion of our patient corresponded to those of previously reported typical cases of MLS syndrome. Our observation further supports the current hypothesis that the phenotypic variation of MLS syndrome represents tissue-different X inactivation rather than different genetic effects of two contiguous genes.

X-linked lymphoproliferative disease (XLP) is a rare familial disorder resulting in selective immunodeficiency to the Epstein-Barr virus (EBV), characterized by uncontrolled proliferation of EBV-infected lymphocytes. Phenotypes of this disease are variable and include fulminant infectious mononucleosis, hypogammaglobulinemia, and malignant lymphoma. In this article, we describe a case of a previously healthy 4-year-old boy with serologic evidence of acute EBV infection who died of fulminant hepatic failure. Histopathological examination of tissue obtained postmortem showed hemophagocytosis and prominent polymorphous infiltrates associated with necrosis in the liver, spleen, and lymph nodes. Semiquantitative polymerase chain reaction (PCR) utilizing primers complementary to the EBV gene LMP2a performed on samples of liver tissue demonstrated approximately 0.6 copies of the EBV gene per cell. Immunohistochemistry demonstrated light chain restriction and PCR studies of the immunoglobulin V-D-J region revealed two strong bands, consistent with a clonal B cell proliferation. Extended family history revealed that the boy's family was followed by the XLP Registry, which was established in 1978 to follow kindreds with XLP. The genetic abnormality associated with XLP has been localized to the Xq25, allowing RFLP analysis to identify female carriers and affected boys.

An adult male house muck shrew with an XXY sex chromosome constitution was found in a laboratory-bred colony. Maternal origin of the additional X chromosome was demonstrated. The external appearance of the animal was normal, but the testes were small and displayed a high density of interstitial cells. The seminiferous tubules were narrow and contained only Sertoli cells.

Purpose: The purpose of this study was to evaluate, among 100 uncleaved oocytes, the incidence of numerical and structural chromosome 21 and X abnormalities and to analyze the influence of various factors, such as in vitro (IVF) indications, follicle stimulation protocols, and women's age., Methods: We investigated 150 uncleaved oocytes from 128 patients after an IVF attempt. After cytogenetic analysis (Giemsa) 100 oocytes (66%) were selected for fluorescence in situ hybridization (FISH). Fluorescent probes for human chromosomes X and 21 were used simultaneously according to standard procedures for their hybridization and detection., Results and Conclusions: We analyzed by the FISH protocol 100 metaphase II oocytes with 22 to 25 chromosomes. Our results demonstrate a high rate of disomy for chromosome 21 in human oocytes. Among them, eight were disomic (8%) and three were nullosomic (3%) for chromosome 21. Only one disomy of chromosome X was noted. The various indications of IVF and the different folliculogenesis stimulating protocols did not seem to influence the results but suggested a correlation between the maternal age and the aneuploidy rate of chromosome 21.

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 42-year old male with short stature, azoospermia and a wide deletion of long arm of Y chromosome. On physical examination, the patient showed height of 149 cm (< 1 degree centile) and reduced volume (3 ml) and consistency of the testes. On hormonal evaluation, he showed increased serum gonadotropins and normal serum testosterone levels though its HCG stimulated levels were limited. Serum thyroid hormones were normal. Serum GH levels in baseline evaluation as well as after GHRH and GHRH + pyridostigmine administration were normal. Serum IGF I levels were lower than normal in baseline evaluation whereas its response to the GH administration was in the normal range. The bilateral testicular biopsy showed tubular atrophy, hyalinosis, interstitial sclerosis and a histological picture of a Sertoli cell only syndrome. Moreover the patient showed arthropathy, otopathy, small chin, small mouth and truncal obesity. On genetic evaluation, the patient showed a 46,X,delY (pter--q11.1:) karyotype and loss of several DNA loci on Yq. In fact he preserved short arm SRY, centromeric DYZ3 and more proximal euchromatic region Yq loci, including DYS270, DYS271, DYS272, DYS11, DYS273, DYS274, DYS148, DYS275, and missed more distal DNA loci from DYS246 to DYZ2. These results disclosed a wide Y long arm deletion, including all hypothized Yq azoospermia loci (except for AZFa and probably for one of the RBM genes, which lie proximally to the deletion) and possibly the Y-specific growth control region (GCY), mapped between DYS11 and DYS246 loci. This deletion is responsible for the complete azoospermia of the patient and probably also for his short stature, even if other factors could be implicated in the statural impairment. It further possibly allowed to relate the GCY gene(s) to the control of GH or IGF-I receptor or post-receptor pathway, being the alteration of this gene(s) consistent with the hormonal pattern of the patient.

We report a case of a short-arm dicentric Y chromosome associated with Sertoli-cell-only tubule. Chromosomal analysis, using G- and C-banding techniques, revealed: 45,X/46,X psu dic(Y) (pter-->q11::q11-->pter)/46,X + mar. Staining by fluorescence in situ hybridization using a Y chromosome centromere-specific DNA probe showed two bright spots in the pseudodicentric Y chromosome and one in the marker chromosome. It is assumed that Sertoli-cell-only tubule is caused by deletion or disruption of the azoospermic factor gene located distal in Yq11.

A patient with mosaic Turner syndrome and normal fertility had three documented pregnancies. She had a 45,X/46,X,r(X) karyotype and did not undergo spontaneous sexual maturation and menarche. Conception occurred while on hormone replacement therapy. Her first pregnancy ended with the birth of a normal 46,XY male, while the third pregnancy resulted in a healthy 45,X/46,X,r(X) female. A review of the literature reveals a myriad of theories to account for the variability of ovarian function in Turner syndrome, but, as yet, there are insufficient data to yield any conclusions. There appears to be an increased risk of trisomy 21 in the offspring of females with Turner syndrome.

A 52-year-old Japanese woman complicated by a sex chromosomal anomaly as a superfemale, a mosaic of XXXXX/XXXX/XXX/XX/XO, with mild mental retardation, was hospitalized for dry mouth, dry eyes, and proteinuria. The sialography of the right parotid gland showed a globular-type gland enlargement. A definite diagnosis of primary Sjögren's syndrome (SS) was made, and further examinations revealed not only typical sicca syndrome but also systemic extraglandular lymphocytic infiltration; interstitial pneumonitis, glomerular- and interstitial nephritis, superficial gastritis, thyroiditis, and a severe excitation conductive impairment of heart. We report a very rare case of superfemale with primary SS which involved systemic organs.

Aggressive fibromatosis (also called deep fibromatosis or desmoid tumor) is a proliferation of cytologically benign-appearing fibrocytes, often resulting in significant functional loss. The nature of the lesion is controversial: some evidence suggests that it is a reactive process, whereas other evidence supports a neoplastic etiology. The pattern of X chromosome inactivation, using a technique based on polymerase chain reaction (PCR) amplification of a hypervariable CAG repeat region flanking Hhal restriction sites of the human androgen receptor gene, was determined in four cases in which cryopreserved tumor and adjacent normal tissue were available. All four tumors demonstrated a monoclonal pattern, while the adjacent normal tissues demonstrated a polyclonal pattern. This demonstrates that aggressive fibromatosis is proliferation of cells derived from a single clone with a growth advantage, and thus is likely a neoplastic process.

A cryptorchid mouse with a 39,X/40,XY chromosome constitution was identified among 414 offspring born in the departmental XO mouse breeding colony. This mouse had a small testis on the left, with no sign of spermatogenesis, and a normal ovary on the right with several corpora lutea.

The trisomy 8 mosaic syndrome (Tr8MS), karyotype 46,XY/47,XY, +8, is a rare multisystem disorder that may be associated with corneal opacity. We report the case of a dysmorphic infant with multiple congenital abnormalities referred to our unit with a congenital corneal opacity. Subsequent chromosomal analysis of peripheral leucocytes demonstrated constitutional Tr8MS. At 4 years of age, lamellar keratoplasty was performed. Histological examination confirmed the lesion to be consistent with a corneal choristoma. Cytogenetic studies using in situ hybridisation techniques showed the presence of trisomic cells in cell culture derived from the tissue in higher proportion (92%) than in the blood (44%). Amplification of the c-myc oncogene on chromosome-8 could not be detected in cells cultured from the corneal lesion. Although not proof, these findings lend support to the concept of the corneal lesion representing a focus of viable trisomic cells rather than an inflammatory response to a nidus of effete cells.

We present the phenotypic, cytogenetic and molecular findings in two dysmorphic and mentally retarded brothers with disomy Xq12-->q13.3. The mother and the grandmother carry the same rearrangement of the X chromosome, which was interpreted as an inverted insertion of the segment (X)(q12-->q13.3) into Xq21.2. The X-inactivation-specific-transcript (XIST) is expressed in the probands mother but is absent in her son, confirming the hypothesis that X inactivation is realized only if two X inactivation centers reside on different X-chromosomes (trans-configuration). In the phenotypically normal mother the aberrant X chromosome was late replicating in all cells, indicating functional monosomy of the constitutional segment trisomy. The phenotype of the brothers is considered to be the consequence of a functional disomy Xq12-->q13.3. The trait combination observed in the brothers was compared with the spectrum of clinical and anthropological traits for proximal Xq disomy in males, elaborated by phenotype analyses of the available literature cases.

Meningiomas are primary brain tumors arising from meningothelial cells. They usually grow slowly and are surgically easy to separate from the brain. A recent clonal analysis of meningiomas, using methylation-sensitive restriction fragment length polymorphisms, suggested a monoclonal origin. Using the same technique but with a highly informative X chromosome probe (M27 beta), we found that 17 (85%) of the 20 meningiomas analyzed were informative. Of the 17 informative tumors, 8 (47%) were monoclonal, 3 (18%) had loss of heterozygosity on the X chromosome, and, unexpectedly, 6 (35%) had a polyclonal pattern. Samples from two areas of one tumor showed a monoclonal pattern and loss of heterozygosity, respectively, on the X chromosome. A review of the histopathological and radiological features of the 17 informative tumors did not help to distinguish the clonal from the polyclonal tumors. We conclude that meningiomas are heterogeneous in clonal composition.

Purpose: The purpose of the study was to investigate homeobox gene expression in human oocytes and preembryos and in postimplantation embryos with impaired embryonic development determined by chromosomal abnormalities., Methods: Reverse transcriptase-polymerase chain reaction (RT-PCR) with intron spanning primer sets for Homeobox gene sequences was used., Results: The homeobox genes HoxA4, HoxA7, HoxB4, and HoxB5 were present in human oocytes and cleaving normal and triploid embryos. The expression pattern was different between chromosomally abnormal and normal first-trimester embryos. Of four homeobox transcripts (HoxA7, HoxB4+ ++, HoxB5, and HoxC6) that are expressed in diploid embryos, only HoxA7, HoxB4 and HoxC6 were present in a trisomy 7 embryo, and only HoxB4 and HoxB 5 in triploid embryos and an embryo with trisomy 9. Cloning experiments revealed differences in the number of homeobox clones obtained from trisomy 7 and control embryos., Conclusions: The transcripts of homeobox genes, HoxA4, HoxA7, HoxB4, and HoxB5, were present in oocytes and cleaving embryos. The pattern of expression of homeobox genes in cultured fibroblasts derived from spontaneously aborted embryos with aneuploidies was different from that in control diploid cells.

XXXXY Syndrome is a rare disorder characterized by multiple anomalies including growth deficiency, hypogenitalism, craniofacial anomalies and dental problems. Some experts feel this syndrome is a derivative of Klinefelter's Syndrome and may be associated with advanced maternal age. The case of a seven year old male with XXXXY syndrome is presented. A dental rehabilitation involving outpatient surgery is described.

The cytogenetic abnormalities of dysmorphic fetuses who died in utero cannot be analyzed reliably by karyotyping. To overcome this obstacle, the authors applied fluorescence in situ hybridization (FISH) to formalin-fixed, paraffin-embedded tissue of two female infants and 13 female fetuses whose phenotypic features suggested possible Turner's syndrome. Previous cytogenetic evaluation of the amnionic fluid showed five were 45,XO karyotype; two were 46,XX karotype; and eight were of unknown karyotype. Karyotyping had been attempted on four of the unknown cases without success. The copy number of X chromosomes were correctly identified by FISH in all previously karyotyped cases. Of the remaining eight cases with unknown karyotype, three appeared to be XX, and five cases were identified as monosomy XO, confirming the suspicion of Turner's syndrome genotype. FISH is useful for confirming suspected Turner's syndrome genotypes in infants and macerated fetuses in which a karyotype cannot be obtained otherwise.

We hypothesize that endometrial carcinoma and their precursors share a monoclonal growth pattern and tested this thesis with archival paraffin-embedded tissues using a polymerase chain reaction-based assay for non-random X chromosome inactivation. Of the 10 well-differentiated endometrial adenocarcinoma cases with heterozygous markers (HUMARA, X-linked androgen receptor gene), 9 had skewed X inactivation consistent with a monoclonal process, and one contained a structurally altered HUMARA gene. X inactivation skewing similar to that of the tumor was seen in matched control polyclonal tissues of 4 (of 9) cases, caused by the small number of endometrial stem cells at the time of embryonic X inactivation. When the polymerase chain reaction assay was applied to four potential endometrial precancers (atypical endometrial hyperplasia) and matched control tissues, two were inconclusive, and two were found to be monoclonal. We conclude that 1) it is essential to include polyclonal control tissues in X inactivation analyses to determine whether skewing is a specific indicator of monoclonality; and 2) endometrial adenocarcinomas and some putative precancers, atypical endometrial hyperplasia, are monoclonal.

We report an anencephalic fetus with acrania, cervicodorsal rachischisis, and a 46,X,del(X)(p22.1) karyotype. Necropsy revealed a left diaphragmatic hernia, ipsilateral lung hypoplasia, and intestinal malrotation. The fetus also had horseshoe kidneys and adrenal gland hypoplasia with absence of the fetal zone.

We report on an infant with double trisomy 48,XXX, + 18. She presented with manifestations of trisomy 18: prominent occiput, microphthalmia, small mouth, micrognathia, malformed ears, congenital heart defect, overlapping fingers, talipes equinovarus, and rockerbottom feet. An extra palmar crease was present only on the right hand. This patient was alive at 12 months. The clinical manifestations are compared with those of 10 previously reported cases.

Longitudinal measurements of height, sitting height and leg length are compared between 11 XXX girls identified by cytogenetic screening, and 16 chromosomally normal controls from the same population using a nonparametric method. While height velocity did not differ between the two groups either during the pubertal or the mid-childhood spurts, leg length velocity was significantly increased during the mid-childhood spurt, between 4 and 9 years of age. A further contribution to the increased leg length came from the slower decline in leg length velocity at the end of the pubertal spurt. The possible mechanisms involved in these changes are discussed.

X-linked hydrocephalus and the X-linked MASA syndrome (Mental retardation. Adducted thumbs, Shuffling gait and Aphasia) both have a variable clinical spectrum with great overlap. Data from DNA linkage analysis placed the locus for both conditions at Xq28. On clinical and molecular grounds it has been hypothesized that both MASA syndrome and X-linked hydrocephalus are caused by a mutation in the same gene at Xq28. There is no significant clinical marker in the obligate female carriers and prenatal diagnosis by ultrasound is not reliable; DNA analysis can offer an improved genetic counseling for the families and more reliable prenatal diagnosis. In the gene encoding for Ll, a neural cell adhesion molecule and located at Xq28, several different mutations have been reported in X-linked hydrocephalus families and in a MASA family. We report data on DNA linkage analysis in 6 families with X-linked hydrocephalus/MASA syndrome. These data illustrate the importance of DNA linkage analysis in the individual family; they also show, however, the problem of studying small families. Genetic heterogeneity cannot be excluded.

X-linked amelogenesis imperfecta is a condition that affects dental enamel characterized by vertical banding of the enamel in heterozygous females in contrast with more uniform appearances in males. The clinical features of a family with amelogenesis imperfecta are described. The disease in this family has been shown to be unlinked to the amelogenin gene locus on the distal short arm of the X chromosome. It maps instead to a locus on the long arm of the X chromosome in the Xq22-q28 region. There was considerable variability in clinical features in affected females in this family in contrast with the more consistent findings in families linked to the amelogenin gene locus region.

X-linked amelogenesis imperfecta has been proven in a number of families to be linked to or involve a variety of mutations in the X chromosome amelogenin gene. The purpose of this study was to characterize the enamel ultrastructure and enamel protein in a kindred affected by X-linked amelogenesis imperfecta. Exfoliated primary teeth were obtained from two related persons (one male, one female) who had X-linked amelogenesis imperfecta with marked hypoplasia. Normal enamel (age and sex matched) was used as the control for all analyses. The teeth were evaluated using light microscopy, scanning electron microscopy, and microradiography. The enamel of the heterozygous female was hypoplastic and rough with marked surface depressions. Enamel beneath these depressions was poorly organized and lacked a prismatic structure. The affected male had very thin enamel (approximately 40 microns) that also lacked an organized structure. Enamel protein from the teeth of the heterozygous female and the control was characterized using amino acid analysis. The protein content of the enamel of the female with amelogenesis imperfecta was 0.40% (N = 1) whereas the control enamel ranged from 0.17% to 0.45% (N = 4; mean = 0.34%). This study indicates that although the enamel in both the male and female with X-linked amelogenesis imperfecta displayed marked structural abnormalities the enamel protein was similar in quantity and amino acid composition for normal and X-linked amelogenesis imperfecta (female) enamel.(ABSTRACT TRUNCATED AT 250 WORDS)

This report suggests the association of congenital diaphragmatic hernia in Simpson-Golabi-Behmel syndrome by describing two unrelated males with this malformation. One male was the maternal half-nephew of our previously reported 8-year-old boy with this syndrome. Review of the skeletal roentgenograms of these 2 affected males, and those of the previously reported 8-year-old, documents flare of the iliac wings, narrow sacroiliac notches, and the presence of two carpal ossification centers as a newborn ("advanced bone age"). We also report the follow-up of the 8-year-old boy, now 16 years old, who continues to have significant overgrowth and speech, dental, developmental, and adjustment problems.

Two azoospermic, infertile men with a pseudodicentric Y chromosome are reported. The small isodicentric Y chromosomes were composed of duplicated short arm and proximal long arm Y, as proven by fluorescence in situ hybridisation using a Y centromere-specific DNA probe, pDP97, and a short arm probe pY-80. Both lacked germinal cells in the gonads. It was assumed that the azoospermia was caused by deletion or disruption of the azoospermic factor gene located at distal Yq11. Patient 2 measured 147 cm (-4.1 SD) in height and so it was assumed that he had also lost the "statural determinants" gene.

Dimensions of the maxilla and mandible were studied in 47,XYY men and their first-degree male relatives, and the results compared with similar studies of other sex-chromosome anomalies. An extra Y chromosome in 47,XYY men caused an increase in palatal growth transversely and anteroposteriorly and in mandibular arch length anteroposteriorly compared to normal men. Palatal height and mandibular width were smaller with this chromosome pattern. Increase in the number of sex chromosomes is associated with changes in palatal and mandibular arch dimensions, more often an increase than a decrease. The findings support earlier observations that the palate becomes shallower with the addition of an X chromosome. It is also apparent that the influence of X and Y chromosomes differs, at least regarding the magnitude of metric changes.

Two patients with Klinefelter's syndrome and three with 47,XYY who had venous ulcers, and one patient with 47,XYY and a post thrombotic limb are described. Sex chromosome abnormalities should be suspected in tall males with leg ulcers, especially those who have no progeny and are relatively young. Venous ulcers may be more common in males with 47,XYY.

Y-autosome translocation is a rare condition. We report here a case of balanced Y-autosome translocation associated with azoospermia. Nineteen cases of a balanced Y-autosome translocation associated with azoospermia are reviewed, and hormone condition and testicular histology are discussed.

Occlusal traits were determined for 47,XYY men and compared with previous determinations of occlusal morphology in other sex-chromosome anomalies and in normal women and men. The 47,XYY men, like 47,XXY men, tended to have a mesial molar occlusion and a mandibular overjet more often than did other groups, while 45,X women (Turner patients) clearly had the highest frequency of distal occlusion and large overjet. The 47,XXY men had the highest frequency of most occlusal anomalies. As a whole, these and earlier findings suggest that the number of X or Y chromosomes is associated negatively with distal occlusion and lateral crossbite, whereas a positive association was found with mesial molar occlusion and scissors bite.

The cause of the Rett syndrome remains unknown but is thought to be related to X-chromosome abnormalities. Restriction fragment length polymorphism analysis was employed to search for X-chromosome DNA rearrangements and uniparental disomy in 16 probands and their families. Eighteen different probes, each specific for an area on either the long or the short arm of the X-chromosome, were used. DNA rearrangements were not detected at any of the tested loci. In addition, at each informative locus evidence of both maternal and paternal contributions was found in all probands. Thus, no evidence of either chromosomal abnormality or uniparental disomy was found in the population studied. If uniparental disomy is indeed a causative genetic mechanism for the Rett syndrome, its occurrence may only be infrequent.

We report a patient with X-linked muscular dystrophy who had rapidly progressive muscle weakness and became wheelchair-bound at age 10 years. Clinically, he was diagnosed as having Duchenne muscular dystrophy; however, he was diagnosed as having Becker muscular dystrophy by dystrophin tests using a C-terminal monoclonal antibody. No immunolabelling was observed with a monoclonal antibody against the N-terminal domain. Multiplex polymerase chain reaction analysis revealed the deletion of exons 3-19. The data suggest that the deletion of the N-terminal domain of dystrophin can cause a severe phenotype even when the C-terminus of the protein is well preserved.

The case of a newborn boy with ichthyosiform erythroderma, asymmetrical shortening of the femur and sectorial cataract is reported. The hyperkeratotic areas cleared within 2 months, resulting in follicular atrophoderma. The clinical findings and course of the disease, and also the histological and ultrastructural features, indicate an X-linked dominant chondrodysplasia punctata (Happle). Since a normal male karyotype (46, XY) is present, a half-chromatid mutation of the maternal gamete and a somatic mutation are considered as possible explanations for this mosaic phenotype.

A 20-week gestational age fetus with full triploidy and multiple malformations is presented. In all examined lymphocytes, fibroblasts and chorionic villi, a 69,XXY karyotype was found. Autopsy examination revealed bilateral ovotestes but, no evidence of Müllerian derivatives.