Israel Medical Association Journal

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: Genes that confer mild or moderate susceptibility to breast cancer may be involved in the pathogenesis of sporadic breast cancer, modifying the phenotypic expression of mutant BRCA1/BRCA2 alleles. An attractive candidate is the insulin-like growth factor I, a known mitogen to mammary ductal cells in vivo and in vitro, whose serum levels were reportedly elevated in breast cancer patients.

Objective: To evaluate the contribution of the IGF-1 gene polymorphism to breast cancer risk by genotyping for a polymorphic allele size in breast cancer patients and controls.

Methods: We analyzed allele size distribution of the polymorphic CA repeat upstream of the IGF-I gene in 412 Israeli Jewish women: 268 women with breast cancer (212-sporadic and 56 carriers of either a BRCA1:or BRCA2 mutation), and 144 controls. Genotyping was accomplished by radioactive polymerase chain reaction of the relevant genomic region and size fractionation on polyacrylamide gels with subsequent auloradiography,

Results: Among women with breast cancer, with or without BRCA germline mutations, 196 and 198 basepair alleles were present in 4.7% (25/536 alleles), compared with 9% (26/288) controls (P = 0.02). This difference was more pronounced and significant in the non-Ashkenazi population. Conversely, the smaller size allele (176 bp) was present in the breast cancer group only {3/536, 0.6%).

Conclusions: The IGF-I polymorphism may serve as a marker for breast cancer risk in the general Jewish population, in particular non-Ashkenazi Jews, but extension and confirmation of these preliminary data are needed.
 

Fanconi anemia is a rare autosomal recessive disorder characterized clinically by congenital abnormalities, progressive bone marrow failure, and a predisposition to malignancy. FA cells are sensitive to DNA cross-linking agents. Complementation analysis of FA cells using somatic cell fusion has facilitated the identification of eight complementation groups, suggesting that FA is a genetically heterogeneous disorder. Six genes (FANCA, FANCC, FANCD2, FANCE, FANGF, FANCG) have been cloned so far. The majority of affected patients belong to FA group A. Of the 32 unrelated Israeli patients with FA that we studied, 6 carried the FANCC mutations and 15 the FANCA mutations. Among the Jewish patients, ethnic-related mutations were common. Recent cumulative evidence suggests that the FA proteins are repair proteins. FANCC, FANCA and FANCG bind and interact in a protein complex found in the cytoplasm and nucleus of normal cells. FANCD2 exists in two isoforms; the long active form, FANCD2-L, is absent from FA cells of all complementation groups. FANCD2 co-localized with BRCA1 in unclear foci, probably as part of a large genomic surveillance complex. Studies using FANCA and FANCC knockout mice suggest that bone marrow precursors express interferon-g hypersensitivity and show progressive apoptosis. The definition of the molecular basis of FA in many affected families now enables prenatal diagnosis.

Background: Familial Mediterranean fever is a genetic disease in which some characteristic gene mutation have been found.

Objective: To analyze the phenotype-genotype correlations in North African Jews and Armedians with FMF.

Methods: We studied MEFV gene mutations and phenotype-genotype correlations in North African Jews and Armedians with Familial Mediterranean Fever living in France.

Results: M694V mutation was the most common mutation in Jews and in Armenians. Patients with M6801 homozygosity or M6801/M694V compound heterozygosity had a phenotype as severe as patients with M694V homozygosity.

Conclusions: This study characterizes the phenotype-genotype in specific ethnic groups of patients with FMF.