Israel Medical Association Journal

Background: Fetal ventriculomegaly is one of the more common fetal anomalies detected during prenatal screening.

Objectives: To assess the rate of genetic aberrations as the cause for ventriculomegaly in these fetuses.

Methods: A historic cohort study was conducted on 164 fetuses with sonographic diagnosis of ventriculomegaly. All cases were analyzed for karyotype and 41 cases were further analyzed by chromosomal microarray (CMA). The study group was subdivided by laterality, severity, and whether the ventriculomegaly was an isolated finding or not. Subgroups were compared and the study group was compared to a control group of 209 fetuses.

Results: Karyotype aberrations were more common among fetuses with ventriculomegaly (6.6%) compared to controls (0%, P < 0.001). CMA aberrations were more common in the non-isolated ventriculomegaly cases (24.1%) compared to controls (6.2%, P = 0.031). The rate of genetic aberrations was not associated with the degree of dilatation or laterality.

Conclusions: It is equivocal whether CMA testing should be conducted on every amniotic fluid sample taken from fetuses with isolated ventriculomegaly. However, if more anomalies are detected during an anatomical survey, CMA analysis should be conducted to decrease oversights of genetic diagnoses.

Background: Biallelic BLM gene mutation carriers are at an increased risk for cancer, including colorectal cancer (CRC). Whether heterozygous BLM gene mutations confer an increased cancer risk remains controversial.

Objectives: To evaluate CRC and endometrial cancer risk in BLM heterozygous mutation carriers.

Methods: Jewish Ashkenazim at high risk for colon or endometrial cancer and endometrial cancer cases unselected for family history were genotyped for the BLM^Ash predominant mutation.

Results: Overall, 243 high-risk individuals were included: 97 men CRC patients (55.12 ± 12.3 years at diagnosis), 109 women with CRC (56.5 ± 13.7 years), 32 women with endometrial cancer (58.25 ± 13.4 years) and 5 women with both CRC and endometrial cancer. In addition, 120 unselected Ashkenazi women with endometrial cancer (64.2 ± 11.58 years) were genotyped. The BLM^Ash mutation was present in 4/243 (1.65%) high-risk patients; 2 CRC (0.97%) 2 endometrial cancer (5.4%), and 1/120 unselected endometrial cancer patients (0.84%). Notably, in high-risk cases, BLM^Ash mutation carriers were diagnosed at a younger age (for CRC 47.5 ± 7.8 years; P = 0.32 ; endometrial cancer 49.5 ± 7.7 years; P = 0.36) compared with non-carriers.

Conclusions: Ashkenazi high risk CRC/endometrial cancer, and women with endometrial cancer have a higher rate of BLM^Ash heterozygous mutation compared with the general population. BLM^Ash heterozygous mutation carriers are diagnosed with CRC and endometrial cancer at a younger age compared with non-carriers. These observations should be validated and the possible clinical implications assessed.

Autoimmune diseases are classic examples of multifactorial disorders in which a large number of genes interact with environmental factors to form the final phenotype. Identification of the genes involved in these diseases is a daunting challenge. Initially the search involved the candidate approach where polymorphisms in suspected genes were tested for association in large cohorts of patients and controls. Today, the most widely used method is genome-wide association studies (GWAS), a method based on screening large panels of patients and controls with hundreds of thousands of single nucleotide polymorphisms (SNPs), with microarray-based technology. Unique families in which autoimmune diseases are caused by single genes are another alternative. The identification of candidate genes is often followed by studies that provide biologic plausibility for the findings. The widely expanding list of genes involved in autoimmune conditions show that the same genes frequently underlie the pathogenesis of different autoimmune diseases. Despite all available resources, the main void of heritability in autoimmune conditions is yet to be discovered. Identification of these genes will help define new biological pathways and identify novel targets for the development of new therapeutic drugs.

Background: Cystinuria is an autosomal recessive disease that is manifested by kidney stones   and is caused by mutations in two genes: SLC3A1 on chromosome 2p and SLC7A9 on chromosome 19q. Urinary cystine levels in obligate carriers are often, but not always, helpful in identifying the causative gene.

Objectives: To characterize the clinical features and analyze the genetic basis of cystinuria in an inbred Moslem Arab Israeli family.

Methods: Family members were evaluated for urinary cystine and amino acid levels. DNA was initially analyzed with polymorphic markers close to the two genes and SLC7A9 was fully sequenced.

Results: Full segregation was found with the marker close to SLC7A9. Sequencing of this gene revealed a missense mutation, P482L, in the homozygous state in all three affected sibs.

Conclusions: A combination of urinary cystine levels in obligate carriers, segregation analysis with polymorphic markers, and sequencing can save time and resources in the search for cystinuria mutations.
 

Background: Familial Mediterranean fever is an autosomal recessive disease characterized by recurrent attacks of fever and serositis. The disease is caused by mutations in the MEFV gene, presumed to act as a down-regulator of inflammation within the polymorphonuclear cells.

Objectives: To present the results of 412 FMF patients genotyped for three MEFV mutations, M694V, V726A and E148Q.

Results: The most frequent mutation, M694V, was detected in 47% of the carrier chromosomes. This mutation, especially common among North African Jewish FMF[1] patients, was not found in any of the Ashkenazi (East European origin) patients. Overall, one of the three mutations was detected in 70% of the carrier chromosomes. M694V/M694V was the most common genotype (27%), followed by M694V/V726A (16%). The full genotype could be assessed in 57% of the patients, and one disease-causing mutation in an additional 26%. Only one patient with the E148Q/E148Q genotype was detected despite a high carrier rate for this mutation in the Jewish population, a finding consistent with a low penetrance of this genotype. The M694V/M694V genotype was observed in 15 patients with amyloidosis compared to 4 amyloidosis patients with other genotypes (P < 0.0001).

Conclusions: Because of low penetrance and as yet other undetermined reasons, mutation analysis of the most common MEFV mutations supports a clinical diagnosis in only about 60% of patients with definite FMF.

_______________________________________

Background: Cystinuria is an autosomal recessive disease that is manifested by the development of kidney stones. Mutations in SLC3A1 cause type I disease, while mutations in SLC7A9 are associated with non-type I disease. In Israel cystinuria is especially common among Libyan Jews who suffer from non-type I disease.

Objectives: To compare clinical manifestations of patients with mutations in SLC3A1 to those with mutations in SLC7A9, and to assess the carrier rate among unaffected Libyan Jewish controls.

Methods: Clinical manifestations were evaluated in patients with mutations in SLC3A1 and in patients with mutations in SLC7A9. Carrier rates for two SLC7A9 mutations were assessed in 287 unaffected Libyan Jewish controls.

Results: Twelve patients with mutations in SLC3A1 were compared to 15 patients with mutations in SLC7A9. No differences were detected between the patients with mutations in SLC3A1 and those with mutations in SLC7A9 in relation to the age of disease onset, the estimated number of stones, the number of invasive procedures, the number of patients receiving drug therapy, or the patients’ urinary pH. Eleven of the unaffected Libyan Jewish controls were found heterozygotes for the V170M mutation, establishing a carrier rate of 1:25. The 1584+3 del AAGT mutation was not found in any of the Libyan Jewish controls.

Conclusion: Mutations in SLC3A1 and SLC7A9 cystinuria patients result in indistinguishable disease manifestations. The high carrier rate among Libyan Jews is a result of a single missense mutation, V170M.
 

Background: Familial Mediterranean fever is a genetic disorder manifested by recurrent attacks of peritonitis, pleuritis and arthritis, and characterized by clinical, histological and laboratory evidence for localized and systemic inflammation. Colchicine treatment usually prevents the attacks and the associated inflammation. Inflammation of atherosclerosis and ischemic heart disease.

Objective: To study the effect of inflammation and its prevention on occurrence of IHD, using FMF as a model.

Methods and Patients: We studied the presence of IHD and its risk factors in 290 FMF patients aged 40 years or more, and in two control groups – 233 spouses of the FMF patients’ and 126 patients with inflammatory diseases obtained from other outpatient clinics. FMF patients were also compared with age and gender-matched individuals from the population reference data of the Israel Ministry of Health.

Results: The prevalence of IHD in FMF patients was significantly lower than in the group of controls from other outpatient clinics (15.5% vs. 30.2% P< 0.05) and comparable with their spouses (11.2%) and with the matched general population in Israel (16%).

Conclusion: These findings suggest that despite the evidence of recurrent inflammation, colchicines-treated FMF patients are not more predisposed to IHD than the normal population.