Search

Mutations in the potassium channel-related gene KCTD7 were described so far in a single family with progressive myoclonus epilepsy. We describe a unique phenotype: acute onset of myoclonus and ataxia, associated with abnormal opsoclonus-like eye movements; improvement of clinical symptoms under steroid treatment; and appearance of epileptic activity on EEG 2 years later without overt seizures. After excluding possible genetic causes, whole-genome exome sequencing was performed in order to identify the causative gene. One heterozygous missense mutation (R84W) was detected by exome sequencing and a large heterozygous deletion of exons 3 and 4 by MLPA analysis. The father is heterozygous for the R84W mutation and the mother is heterozygous for the exon 3+4 deletion. The mutation affects a highly conserved segment of the predicted protein, changing a basic amino acid into neutral. The large deletion probably results in a truncated protein. The different phenotype broadens the spectrum of KCTD7-related diseases. Therefore, patients diagnosed as having opsoclonus-myoclonus with an atypical course should be evaluated for KCTD7 mutations.

Acute myeloid leukemia (AML) with a complex karyotype (CK) has frequent alterations in TP53 and a very poor prognosis. We examined whether a prompt and simple fluorescence in situ hybridization (FISH) analysis for 17p13 deletion at diagnosis has a predictive value for response to therapy and overall survival in subgroups of AML. In 15 patients with a normal karyotype the TP53 FISH analysis was normal, whereas in 16 patients with CK 75% had only one copy of the TP53 allele. The deletion was also detected in 33% of six patients with monosomy or partial monosomy of chromosome 5, 7, 9, or 12. This loss of TP53 correlated significantly with a poor response to chemotherapy, and the median survival time of these patients was shorter. TP53 FISH analysis carried out at diagnosis has a predictive value with respect to chemotherapy response and can therefore facilitate a rapid decision on treatment strategies.

Summary Introduction X-linked adrenal hypoplasia congenita (AHC) is a rare disorder caused by mutations or complete deletion of the NR0B1 gene that encodes the DAX-1 protein, an orphan member of the nuclear receptor superfamily. AHC is characterized by adrenal insufficiency in infancy and early childhood. Later, hypogonadotropic hypogonadism (HH) manifests as pubertal failure. Patients and methods We evaluated the clinical, endocrine and molecular characteristics of 12 AHC patients from 5 families diagnosed between 1984 and 2007 in Israel. Results Most of the boys (10/12) presented with signs of adrenal insufficiency such as salt wasting and failure to thrive during the neonatal period. Aldosterone deficiency usually preceded cortisol deficiency requiring early mineralocorticoid therapy. Serum cortisol levels in the first weeks of life varied from very low to high levels ( 1776 nmol/l). Five boys showed signs of precocious sexual development during infancy and childhood, including enlargement of the penis and testes. In four patients the initial diagnoses were erroneous. Molecular analysis of the NR0B1 gene identified point mutations in six patients including a novel splice site mutation in one patient and his family (IVS1-1G→C). Contiguous gene deletion was found in six patients from two families who manifested impaired mental development. Conclusions In X-linked AHC caused by different molecular defects in NR0B1 gene, the clinical spectrum of the disease is quite variable and precocious sexual development is a prominent feature. Genetic testing is indicated in boys presenting with salt-wasting with or without cortisol deficiency if congenital adrenal hyperplasia has been ruled out.

Rett syndrome is a neurodevelopmental disorder characterized by cognitive and adaptive regression with autistic features, loss of acquired skills, and stereotypic hand movements that almost exclusively affects females. It is an X-linked dominant disorder, with presumed lethality in males. Nonetheless, there are a few descriptions of males suspected of having Rett syndrome. With the recent discovery that the MECP2 gene is responsible for most cases of Rett syndrome, it is possible to molecularly assess cases of affected males by direct sequencing analysis. We describe an Israeli family consisting of a female having classic Rett syndrome and a male sibling with severe neonatal encephalopathy. Molecular analysis revealed that both sister and brother have the same MECP2 gene mutation; however, their mother does not. This case, as well as other published studies of males with MECP2 mutations, reveals that the clinical manifestations in viable males vary from neonates with severe encephalopathy to adults with mental retardation and demonstrate genotype-phenotype correlations. (J Child Neurol 2002;17:20-24).

Turcot's syndrome is a rare heritable complex that is characterized by an association between a primary neuroepithelial tumor of the central nervous system and multiple colonic polyps. The aim of this study was to analyze genetic alterations in a case of Turcot's syndrome in a 10.5-year-old boy in whom a colorectal tumor developed 3.5 years following astrocytoma. An APC germline non-sense mutation at codon 1284 leading to a truncated protein was identified, as was a somatic p53 mutation in the colorectal carcinoma in exon 7, codon 244. The latter was not identified in the primary astrocytoma. However, immunohistochemistry revealed high p53 protein expression in both tumors, suggesting an additional p53 mutation in the primary astrocytic tumor. The diverse p53 mutations observed in this unique syndrome in two different sites and stages of the disease may shed light on the multistep progression of the malignant events.

Fragile X syndrome, a common cause of intellectual disability, is usually caused by CGG trinucleotide expansion in the FMR1 gene. CGG repeat size correlates with expansion risk. Premutation alleles (55–200 repeats) may expand to full mutations in female meiosis. Interspersed AGG repeats decrease allele instability and expansion risk. The carrier rate and stability of FMR1 alleles were evaluated in large cohorts of Ashkenazi and non-Ashkenazi women. A total of 4,344 Ashkenazi and 4,985 non-Ashkenazi cases were analyzed using Southern blotting and polymerase chain reaction between 2004 and 2011. In addition, AGG interruptions were evaluated in 326 Ashkenazi and 298 non-Ashkenazi women who were recruited during 2011. Both groups had major peaks of 30 and 29 repeats. Ashkenazi women had a higher frequency of 30 repeats and a lower frequency of other peaks (P < 0.0001). A higher rate of premutations in the 55–59 repeats range (1:114 vs. 1:277) was detected among the Ashkenazi women. Loss of AGG interruptions (

A 7-month-old boy with gross motor delay and failure to thrive presented with rhabdomyolysis following an acute asthmatic episode. During hospitalization an electrocardiographic conversion to a Wolff-Parkinson-White type 1 (WPW) pattern took place. Duchenne muscular dystrophy (DMD) was suspected based on elevated creatine kinase (CK) serum levels, muscle biopsy, and family history. The diagnosis was confirmed by molecular analysis, which documented a deletion corresponding to cDNA probe 1-2a in the dystrophin gene, in the propositus and in an affected male cousin of his mother. "Idiopathic" hyperCKemia was found in the propositus, his father, and 5 of his relatives. We suggest that the unusually early and severe manifestations of DMD in this patient may be related to the coincidental inheritance of the maternal DMD gene and of a paternal gene, causing hyperCKemia.

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are allelic disorders caused by mutations in the X-linked dystrophin gene. The most common mutations in western populations are deletions that are spread non-randomly throughout the gene. Molecular analysis of the dystrophin gene structure by hybridization of the full length cDNA to Southern blots and by PCR in 62 unrelated Israeli male DMD/BMD patients showed deletions in 23 (37%). This proportion is significantly lower than that found in European and North American populations (55-65%). Seventy-eight percent of the deletions were confined to exons 44-52, half of these to exons 44-45, and the remaining 22% to exons 1 and 19. There was no correlation between the size of the deletion and the severity of the disease. All the deletions causing frameshift resulted in the DMD phenotypes.

Purpose: To determine the frequency of SMN1 deletion carriers in the Israeli population and to assess the feasibility of population screening for spinal muscular atrophy. Methods: A total of 6394 individuals without family history of spinal muscular atrophy underwent genetic screening by multiplex ligation-dependent probe amplification, designed to detect SMN1 exon 7 and exon 8 copy number. Results: One hundred fifty-nine individuals carried an SMN1 heterozygous exon 7 deletion, yielding a carrier frequency of 1:40. About 10.8% of individuals were found to carry two or more SMN1 exon 7 copies on the same chromosome (cis configuration). This implies that some deletion carriers may not be detected by multiplex ligation-dependent probe amplification or similar quantitative methods. The acceptance of spinal muscular atrophy screening among women undergoing testing for fragile X syndrome and cystic fibrosis reached 93%. Conclusions: Currently used molecular techniques cannot detect about 5% of spinal muscular atrophy carriers with a cis configuration or individuals with SMN1 sequence mutations and de novo deletions. Thus, it is estimated that the spinal muscular atrophy carrier detection rate is about 90%. Given the severity of spinal muscular atrophy, the relatively high carrier frequency, and the estimated detection rate, we conclude that population-based screening for spinal muscular atrophy is feasible and acceptable.

Duchenne muscular dystrophy (DMD) results from mutations in the X-linked gene coding for the muscular protein dystrophin. The isolation of genomic and cDNA probes for this gene has greatly facilitated the detection of DMD carriers, which previously relied mainly on measurements of serum creatine kinase (CK), and has enabled prenatal diagnosis of this disease. However, the relatively large size of the gene and the high frequency of recombination and mutation events within the dystrophin locus continue to pose difficulties in the genetic counselling and prenatal diagnosis of DMD, and render the conclusions of molecular analysis less clear cut. This communication presents examples of two such difficulties: the distinction between sporadic and inherited cases in families with a single patient and normal CK levels in all females, and the distinction between mutant and normal dystrophin alleles in families in which the patients have died. The combined use of genomic and cDNA probes allows one to make these distinctions. An additional complicating factor, gonadal mosaicism, is demonstrated.

Objective: Spinal muscular atrophy (SMA) is a common autosomal recessive neuromuscular disorder caused in most patients by homozygous deletion of the SMN1 gene. For a carrier couple at a 25% risk of affected offspring, preimplantation genetic diagnosis (PGD) offers an alternative to prenatal diagnosis and termination of affected pregnancies. Our objective was to develop an accurate and reliable single-cell multiplex nested PCR analysis for PGD of SMA. Methods: The method was developed on single blood leukocytes, obtained from healthy controls and an adult SMA type III patient with a known homozygous deletion of SMN1 exon 7 and 8. Multiplex nested PCR on single cells was used to co-amplify exons 7 and 8 of SMN. Additional multiplexing was performed with the ZFX/ZFY gene for sexing. Following successful establishment of the multiplex nested PCR protocol in single leukocytes, the technique was employed for PGD in 4 patients for a total of 7 cycles. In 2 patients, sexing was simultaneously performed using ZFX/ZFY. Results: 220 single leukocytes from a normal individual and 220 from an SMA patient were analyzed. Exon 7 of SMN1 was amplified in 99% of normal single leukocytes and in none of the SMA-affected leukocytes. Exon 7 of SMN2 was amplified in 100% of both normal and SMA-affected leukocytes. Exon 8 of SMN1 was amplified in 98% of normal cells and in none of the SMA-affected leukocytes. Exon 8 of SMN2 was amplified in 96% of both normal and SMA-affected leukocytes. Amplification efficiency was 99% for ZFX/ZFY. There were no false-negative results and no contamination was detected in all wash-drop blanks tested. Seven PGD cycles were performed in 4 SMA-carrier couples with successful molecular analysis of 34 embryos and a total of 15 normal embryos transferred in 7 cycles. One clinical pregnancy has resulted in the delivery of a healthy male. Amniocentesis performed at 17 weeks confirmed the correct diagnosis for both SMA and sexing. Conclusions: These results suggest that our multiplex nested PCR protocol offers an efficient and accurate method for PGD of SMA while enabling the simultaneous analysis of an additional loci.

This report describes molecular analysis of the MECP2 gene in 37 Israeli patients suspected of having Rett syndrome (RTT). The patients were from various Jewish ethnic groups and from Arabic origin. Of the 17 patients with classical RTT, bi -directional sequencing of the coding exons revealed MECP2 mutations in 14 patients. About 66% of the mutations were located in prev iously described hot-spots. One case presented a novel mutation (141insA). Mutation-negative patients were further analyzed by Southern blot, which detected a novel gross rearrangement in another classical case. Altogether, detection rate in classical cases was 88%. In a non-classical case, a novel missense mutation (1451G>C) was detected in an affected girl and in her normal father, suggesting that this is a non-pathogenic alteration. Another variant (1461+96insA) was detected in an affected girl and in he r healthy mother and also in another affected girl and her healthy father, suggesting that this variant too, is non-pathogenic. No significant difference in mutation type was noted among the different ethnic groups. In one familial case, the same mutation was detected in two sibs but not in their mother, suggesting germ-line mosaicism. Our results suggest that mutation-negative cases should be further assessed for gross rearrangements and that molecular analysis of the parents is often required when previously undescribed sequence alterations are detected. © ?2002 Wiley-Liss, Inc.

Background & Aims: Israeli Jews of European birth, i.e., Ashkenazim, have the highest colorectal cancer incidence of any Israeli ethnic group. The I1307K APC gene variant was found in 6.1% of American Jews, 28% of their familial colorectal cancer cases, but not in non-Jews. We assessed the I1307K prevalence in Israeli Jews of differing ethnic origin and risk for colorectal cancer. Methods: DNA samples from 500 unrelated Jews of European or non-European origin, with or without a personal and/or family history of neoplasia, were examined for the I1307K variant by the allele-specific oligonucleotide (ASO) method. Results: In persons at average risk for colorectal cancer, I1307K was found in 5.0% of 120 European and 1.6% of 188 non-European Jews ( P = 0.08). It occurred in 15.4% of 52 Ashkenazi Israelis with familial cancer ( P = 0.02) and was not detected in 51 non-European Jews at increased cancer risk. Colorectal neoplasia occurred personally or in the families of 13 of 20 Ashkenazi I1307K carriers, 8 of whom also had a personal or family history of noncolonic neoplasia. Conclusions: The I1307K APC variant may represent a susceptibility gene for colorectal, or other, cancers in Ashkenazi Jews, and partially explains the higher incidence of colorectal cancer in European Israelis. GASTROENTEROLOGY 1999;116:54-57

We describe two brothers with clinical and histological findings of type 2 spinal muscular atrophy (SMA) associated with small head circumference (

We have examined the expression of several Duchenne muscular dystrophy (DMD) gene products in amniotic fluid (AF) and chorionic villus sampling (CVS) cells. Variable amounts ofdystrophin could be detected in most CVS and AF samples by immunoprecipitation followed by Western blot analysis. PCR analysis demonstrated the presence of the muscle type dystrophin mRNA in all AF cell cultures. The brain type dystrophin mRNA was also detected in some of these cultures. These DMD gene transcripts are of fetal origin and are produced by most or all clonable AF cells. The results may facilitate the development of a method for prenatal diagnosis of DMD, based on the expression of the gene in AF and CVS cells.

Familial adenomatous polyposis (FAP) is caused by germline mutations in the APC gene. This study included 71 Israeli families referred for molecular analysis of the APC gene. Analysis was performed by the protein truncation test (PTT) of exon 15, and if negative, by direct sequencing of exon 1 to 14. Mutations were found in 36 (50.7%) probands. Mutation detection rates depended on the pattern of referral, such that among the 40 probands referred from the Service for Hereditary Cancer the mutation detection rate was 70%, whereas among the 31 probands referred by other gastroenterologists detection rate was significantly lower (25.8%). Of the 36 mutations detected, 21 were within exon 15, 13 within exons 1 to 14 and 2 were newly-described splicing mutations in introns 9 and 14. A relatively high proportion of the mutations was detected in exon 9 (6/36), five of them newly described. Altogether, we describe here 17 new mutations. Within the two major ethnic groups in Israel, patients of Ashkenazi and non-Ashkenazi origin, there was no significant differences in the mutation detection rate or the distribution of mutations within the APC gene. No founder mutation was detected in any of these populations. Our data confirm that higher detection rates may be expected in patients referred by clinical services specializing in hereditary colon cancer. These results further underscore the importance of complete analysis of all exons and exon/intron boundaries, in order to achieve maximal detection rate in patients suspected of FAP.

Emery-Dreifuss Muscular Dystrophy (EMD or EDMD) is a rare X-linked recessive disorder, characterized by progressive muscle wasting and weakness, contractures, and cardiomyopathy, manifesting as heart block. Mutation analysis at the EMD gene locus was performed in 4 unrelated Israeli families with X-linked EMD and in one sporadic case. In the 4 families 4 different mutations were found, 3 of which were novel. These included two frame shift mutations in exon 2 (333delT and 412insA) and one base pair substitution at the consensus +1 donor splice in intron 5 (1429GA). The fourth mutation in exon 6 (1675-1678delTCCG) has been previously described. No mutations were identified in the one sporadic case. Two of the three novel mutations were found in exon 2. A summary of the previously published mutations described in the EMD Mutation Database (http://www.path.cam.ac.uk/emd/) as well as the mutations described in our study suggest that the distribution of mutations in EMD gene is not entirely random and that exon 2 is prone to mutations. Hum Mutat 17:522, 2001. © 2001 Wiley-Liss, Inc.