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Biomedical subjects

Z Borochowitz

Publications and source records attributed to Z Borochowitz.

At least 19 recordsLinked to original sources

Mucolipidosis III type C: first-trimester biochemical and molecular prenatal diagnosis.

OBJECTIVES: Mucolipidosis IIIC (MLIIIC) is a rare autosomal recessive lysosomal storage disease resulting from defective mannose 6-phosphate-dependent lysosomal enzyme trafficking; mutations of the gamma subunit of N-acetylglucosamine-1 phosphotransferase (GINAcPT) were recently found to cause its pathogenesis. We report here for the first time prenatal diagnosis (PND) for MLIIIC by means of chorionic villous sampling (CVS). METHODS AND RESULTS: A fetus in a large Bedouin-Moslem family was found to be homozygous for the founder haplotype and the mutational SSCP pattern of MLIIIC. The diagnosis was confirmed by markedly reduced lysosomal enzyme activities in cultured chorionic villi. The molecular identification of the disease-causing mutation in this large Bedouin-Moslem kindred permitted, for the first time, identification of carriers and couples at risk. CONCLUSIONS: The feasibility of early PND for a progressive disabling disease is important for its prevention. Nevertheless, the feasibility of PND raises a serious dilemma since affected individuals might have a variable phenotype and the disease is progressive and non-lethal. In addition, religious and social constraints are important factors to be taken into consideration in the genetic counseling of couples at risk.

Arabs↗

DNA based prenatal testing for the skin blistering disorder epidermolysis bullosa simplex.

Epidermolysis bullosa simplex (EBS) is a skin fragility disorder in which mild physical trauma leads to blistering. The phenotype of the disorder is variable, from relatively mild affecting only the hands and/or feet, to very severe with widespread blistering. For the severest forms of EBS there is a demand for prenatal diagnosis which until now has involved a fetal skin biopsy in the second trimester. The identification of mutations in the genes encoding keratins K5 and K14 as the cause of EBS opens up the possibility of much earlier diagnosis of the disease. We report here four cases in which prenatal testing was performed. In three of the cases the genetic lesions were unknown at the start of the pregnancy, requiring the identification of the causative mutation prior to testing fetal DNA. In two of the four cases novel mutations were identified in K14 and in the two remaining families, a previously identified type of mutation was found. Fetal DNA, obtained by chorionic villus sampling or amniocentesis, was analysed for the identified mutations. Three of the DNA samples were found to be normal; a mutant K14 allele was identified in the fourth case and the pregnancy was terminated. These results demonstrate the feasibility of DNA-based prenatal testing for EBS in families where causative mutations can be found.

Amino Acid Sequence↗

Achondroplasia in diverse Jewish and Arab populations in Israel: clinical and molecular characterization.

BACKGROUND: Achondroplasia is the most frequent form of disproportionate short stature, characterized by rhizomelic shortening of the limbs. This disorder is inherited as an autosomal dominant trait, although most of the cases are sporadic, a result of a de novo mutation. A recurrent glycine to arginine mutation at codon 380 (G380R) in the transmembrane domain of the fibroblast growth factor receptor 3 gene was found to cause achondroplasia among different populations. This is most uncommon in other autosomal dominant genetic diseases. OBJECTIVES: To determine whether this mutation is also common among Jewish patients from diverse ethnic groups and among the Arab population in Israel. METHODS: We examined the G380R mutation (G > A and G > C transition) and the mutation G375C (G > T transition at codon 375) in 31 sporadic patients and in one family diagnosed clinically to have achondroplasia. RESULTS: We found the G > A transition at codon 380 in 30 of our patients and the G > C transition in one patient. We were not able to detect any of the three mutations in two patients with an atypical form of achondroplasia. CONCLUSIONS: Our results further support the unusual observation that nucleotide 1138 of the FGFR3 gene is the most mutable nucleotide discovered to date across different populations.

Achondroplasia↗

Autosomal-recessive omodysplasia: prenatal diagnosis and histomorphometric assessment of the physeal plates of the long bones.

Second-semester ultrasonography of a female fetus documented short femora and humeri and dislocation of the radii. Based on the clinical and postmortem radiological findings, autosomal-recessive omodysplasia was diagnosed. The physeal plates of the long tubular bones were assessed by computer-assisted image analysis. The dimensions and orientation of the chondrocytic lacunae in the physeal plates of the omodysplastic fetus were compared with those in the physeal plates of fetuses without gross limb abnormalities (oligohydramnios, n = 2; hydrocephalus, n = 2; Down syndrome, n = 1). The pathological characteristics of the omodysplastic physeal plates were an expanded zone of proliferating cartilage and an increased number of closely packed, small chondrocytes. We propose that a genetic, functional deficiency of the physeal cells, underlying the short-limbed dwarfism of autosomal-recessive omodysplasia, is partially compensated, albeit ineffectively, by an increased number of small chondrocytes in the proliferating zone of the physeal plate.

Abortion, Therapeutic↗

Prevalence of glucocerebrosidase mutations in the Israeli Ashkenazi Jewish population.

Gaucher disease is the most prevalent inherited disease among Ashkenazi Jews. It is very heterogeneous due to a large number of mutations within the glucocerebrosidase gene, whose impaired activity is the cause for this disease. Aiming at determining Gaucher carrier frequency among the Ashkenazi Jewish population in Israel, 1,208 individuals were molecularly diagnosed for six mutations known to occur among Ashkenazi Jewish Gaucher patients, using the newly developed Pronto Gaucher kit. The following mutations were tested: N370S, 84GG, IVS2+1, D409H, L444P, and V394L. Molecular testing of these mutations also allows identification of the recTL allele. The results indicated that Gaucher carrier frequency is 1:17 within the tested population. The prevalence of N370S carriers is 1:17.5. This implies that approximately 1:1225 Ashkenazi Jews will be homozygous for the N370S mutation. Actually, in our study of 1,208 individuals one was found to be homozygous for the N370S mutation. The actual number of known Ashkenazi Jewish Gaucher patients with this genotype is much lower than that expected according to the frequency of the N370S mutation, suggesting a low penetrance of this mutation. Results of loading experiments in cells homozygous for the N370S mutation, as well as cells homozygous for the L444P and the D409H mutations, exemplified this phenomenon.

Cells, Cultured↗

Genetic heterogeneity of Saethre-Chotzen syndrome, due to TWIST and FGFR mutations.

Thirty-two unrelated patients with features of Saethre-Chotzen syndrome, a common autosomal dominant condition of craniosynostosis and limb anomalies, were screened for mutations in TWIST, FGFR2, and FGFR3. Nine novel and three recurrent TWIST mutations were found in 12 families. Seven families were found to have the FGFR3 P250R mutation, and one individual was found to have an FGFR2 VV269-270 deletion. To date, our detection rate for TWIST or FGFR mutations is 68% in our Saethre-Chotzen syndrome patients, including our five patients elsewhere reported with TWIST mutations. More than 35 different TWIST mutations are now known in the literature. The most common phenotypic features, present in more than a third of our patients with TWIST mutations, are coronal synostosis, brachycephaly, low frontal hairline, facial asymmetry, ptosis, hypertelorism, broad great toes, and clinodactyly. Significant intra- and interfamilial phenotypic variability is present for either TWIST mutations or FGFR mutations. The overlap in clinical features and the presence, in the same genes, of mutations for more than one craniosynostotic condition-such as Saethre-Chotzen, Crouzon, and Pfeiffer syndromes-support the hypothesis that TWIST and FGFRs are components of the same molecular pathway involved in the modulation of craniofacial and limb development in humans.

Acrocephalosyndactylia↗

Inherited inverted duplication of X chromosome in a male: report of a patient and review of the literature.

Nineteen cases of duplication of segments of the long arm of chromosome X have been published in 13 males and in 6 females. We report an additional case of a male with growth and mental retardation, growth hormone deficiency, compensated primary hypothyroidism, distinctive anomalies of the face, hypoplastic genitalia, and hypotonia in whom inverted duplication of a segment in the long arm of X chromosome was diagnosed, 46,Y, dup (X)(q21.2q13.3), and mosaicism was demonstrated in his mother's X chromosome. The rearranged segment was diagnosed utilizing high resolution G-band technique and FISH studies, using chromosome X total chromosome probe and DNA XIST probe. This appears to be the first report of a patient with duplication of Xq and hypothyroidism.

Child, Preschool↗

Preauricular tags and pits in the newborn: the role of hearing tests.

The aim of this study was to determine the role of audiometry in a group of newborn infants with preauricular tags or pits. During the 2 years of prospective study, 26 infants were born with preauricular tags or pits (5.7 per 1,000 livebirths) and were assessed for hearing impairment by performing behavioural audiometry on day 3 of life and brainstem-evoked response audiometry at 4 months of age. Five infants had associated congenital anomalies (19%). The behavioural audiometry was abnormal in seven infants (27%). The evoked response audiometry was abnormal in 4/23 (17%) newborn infants with isolated tags or pits, and revealed both conductive and/or sensorineural hearing impairment. The incidence of hearing impairment with isolated preauricular tag/pit was significantly higher (p < 0.001) than the incidence reported in preschool children. We conclude that hearing assessment is recommended in the routine evaluation of the newborn with isolated preauricular tags or pits. This policy may facilitate early diagnosis and treatment of hearing impairment in this population.

Audiometry↗

Predisposition to the fragile X syndrome in Jews of Tunisian descent is due to the absence of AGG interruptions on a rare Mediterranean haplotype.

We have studied the ethnic distribution of the fragile X syndrome in Israel and have found that 36/136 (26.5%) of apparently unrelated pedigrees were of Tunisian Jewish descent. The Tunisian Jews, however, constitute only 2%-3% of the general Israeli population, identifying the first ethnic group significantly (P < .001) predisposed to the development of this disease. Associated with this increase in disease prevalence, we have found an unusually high incidence of FMR1 CGG repeats devoid of AGG interruptions among the normal Tunisian Jewish population (30/150, or 20.0%). Furthermore, the proportion of these alleles beyond the FMR1 CGG repeat instability threshold (>35 repeats) (8/150, or 5.3%) was significantly greater (P < .04) than that proportion found among non-Tunisian Jewish controls in Israel (1/136). Haplotype analysis has indicated that these large uninterrupted CGG repeat alleles are present on a previously unreported (DXS548-FRAXAC1-FRAXAC2) haplotype that accounts for all observed cases of disease among Tunisian Jewish X chromosomes. The high prevalence of disease among Tunisian Jews, we suggest, is due to a founder effect of this rare haplotype, which is completely devoid of AGG interruptions in the Jewish population of Tunisia.

Arabs↗

Interstitial deletion (6)q13q15.

We report on a 2-year-old child with psychomotor retardation, facial and urogenital anomalies. His chromosome constitution was 46,XY, del(6)(q13q15). This case further contributes to the karyotype-phenotype correlation of proximal deletion 6q syndromes.

Abnormalities, Multiple↗

DNA-based carrier detection and prenatal diagnosis of tyrosinase-negative oculocutaneous albinism (OCA1A).

We describe molecular prenatal diagnosis and carrier detection of tyrosinase-negative oculocutaneous albinism (OCA1A) in two families. In one family, we carried out DNA-based prenatal diagnosis of OCA1A. In the other family, mutation analysis and carrier detection obviated the need for prenatal diagnosis. Molecular analysis is safer and probably more accurate than fetoscopy and fetal scalp biopsy, and should become the method of first choice for prenatal diagnosis of OCA1.

Albinism, Oculocutaneous↗

Down syndrome prevention program in a population with an older maternal age.

OBJECTIVE: To investigate the effect of a relatively high proportion of pregnant women 35 years and older on the efficacy of prenatal screening for Down syndrome. METHODS: We obtained information on normal and abnormal cytogenetic and maternal serum marker studies for 1990 and 1992 from all 11 public and two private cytogenetic laboratories operating in Israel. RESULTS: In the Jewish Israeli population, 16.2-17.1% of all pregnant women are at least 35 years old. Thus, prenatal testing of all pregnant women at least 35 years old could have identified 62.8-66.5% of all Down syndrome cases. Screening by maternal serum markers would classify 9.28% of pregnancies as being at high risk for Down syndrome (greater than 1:386 at birth). The percentage of Down syndrome cases detected prenatally increased from 78 of 147 (53%) to 123 of 163 (75%) as a result of the increased use of prenatal testing from 11.3% to 19.4% of all pregnancies in 1990 and 1992, respectively. CONCLUSIONS: In a population with a high proportion of mothers at least 35 years old, as in the Jewish population in Israel, screening by maternal serum markers instead of by maternal age alone would leave the Down syndrome detection rate unchanged, but would lower the amniocentesis rate from 16.2-17.1% to 9.28%. In addition to the reduction in the expected fetal loss as a result of post-amniocentesis spontaneous abortion, this policy would also pay the cost of maternal serum marker testing of the entire pregnant population.

Adult↗

Deletion of the short arm of chromosome 10 (10p13): report of a patient and review.

Since the first description by Elliot et al. [1970, Am J Dis Child 119:72-73] of a probable partial deletion of chromosome 10p, 17 other cases have been reported. The phenotypic expression is variable, but the craniofacial malformations constitute a more consistent finding. The 10p deletion syndrome has been associated with the DiGeorge anomaly in several patients. We report on an additional case of 10p deletion syndrome and review the literature.

Child, Preschool↗

Early prenatal diagnosis of polycystic pancreas with narrow thorax and short limb dwarfism.

We describe the ultrasound findings of polycystic pancreas with short rib dwarfism in the early second trimester. Radiologic, morphologic, and histologic examination after pregnancy termination confirmed the findings and also disclosed dysplastic kidneys. The skeletal anomalies are similar to those in Verma Naumoff type of short rib polydactyly, but the extraskeletal malformations have never been reported before in this syndrome.

Abnormalities, Multiple↗