Israel Medical Association Journal

Background: Gaucher disease is the most prevalent inherited disorder among Ashkenazi Jews (carrier frequency of about 6%) and six mutations account for about 96% of their mutant alleles. Two mutations, N370S and R496H, have been reported only in mildly affected or asymptomatic patients, Due to the rarity of R496H, it was recommended that it be excluded from screening programs. 

Objectives: To verify the frequency and trace the origin of Gaucher mutations in screened individuals whose Ashkenazi ethnicity was confirmed by the birthplace of their grandparents.

Methods: We conducted a retrospective analysis of the screened results for the period 2006–2011. Mutations were identified by restriction analysis, Tag-It^TM detection system, Pronto® diagnostic kit and Nanogen technology (NanoChip® 400).

Results: The heterozygote frequency of eight mutations was estimated in a cohort of 16,910 alleles. Two mutations, N370S and R496H, were the most frequent in our population. However, while the occurrence of N370S carriers was similar to other reports (1:19.4), that of R496H carriers was considerably elevated (1:207). Examination of the screened individuals' ethnicity showed a significant difference in the distribution pattern of the country of origin between the carriers of these two mutations.

Conclusions: The origin pattern differences between the two groups of heterozygotes might reflect a separate geographic region of introduction for various mutations. As a result, secondary subgroups could be formed within the Ashkenazi population. This might clarify the dissimilarities in the occurrence of R496H mutation reported by various centers. 

Background: Fanconi anemia complementation group C and Bloom syndrome, rare autosomal recessive disorders marked by chromosome instability, are especially prevalent in the Ashkenazi* Jewish community. A single predominant mutation for each has been reported in Ashkenazi Jews: c.711+4A→T (IVS4 +4 A→T) in FACC[1] and BLM^Ash in Bloom syndrome. Individuals affected by both syndromes are characterized by susceptibility for developing malignancies, and we questioned whether heterozygote carriers have a similarly increased risk.

Objectives: To estimate the cancer rate among FACC and BLM^Ash carriers and their families over three previous generations in unselected Ashkenazi Jewish individuals.

Methods: We studied 42 FACC carriers, 28 BLM^Ash carriers and 43 controls. The control subjects were Ashkenazi Jews participating in our prenatal genetic screening program who tested negative for FACC and BLM^Ash. All subjects filled out a questionnaire regarding their own and a three-generation family history of cancer. The prevalence rates of cancer among relatives of FACC, BLM^Ash and controls were computed and compared using the chi-square test.

Results: In 463 relatives of FACC carriers, 45 malignancies were reported (9.7%) including 10 breast (2.2%) and 13 colon cancers (2.8%). Among 326 relatives of BLM^Ash carriers there were 30 malignancies (9.2%) including 7 breast (2.1%) and 4 colon cancers (1.2%). Controls consisted of 503 family members with 63 reported malignancies (12.5%) including 11 breast (2.2%) and 11 colon cancers (2.2%).

Conclusions: We found no significantly increased prevalence of malignancies among carriers in at least three generations compared to the controls.

Background: Germline mutations in BRCA1 and BRCA2 genes account for only 20–40% of familial breast cancer cases. The CHEK2 gene encodes a checkpoint kinase, involved in response to DNA damage, and hence is a candidate gene for breast cancer susceptibility. Indeed, the CHEK2*1100delC truncating mutation was reported in a subset of mostly North European breast cancer families. The rate of the CHEK2*1100delC variant in the Ashkenazi* Jewish population was reported to be 0.3%.

Objectives: To evaluate whether CHEK2 germline mutations contribute to a breast cancer predisposition in Ashkenazi-Jewish high risk families.

Methods: High risk Ashkenazi Jewish women, none of whom was a carrier of the predominant Jewish mutations in BRCA1/BRCA2, were genotyped for germline mutations in the CHEK2 gene by exon-specific polymerase chain reaction followed by denaturing gradient gel electrophoresis and sequencing of abnormally migrating fragments.

Results: Overall, 172 high risk women were genotyped: 75 (43.6%) with breast cancer (average age at diagnosis 49.6 ± 9.6 years, mean ± SD) and 97 asymptomatic individuals (age at counseling 48.3 ± 8.2 years). No truncating mutations were noted and four previously described missense mutations were detected (R3W 1.2%, I157T 1.2%, R180C 0.6% and S428F 5%), one silent polymorphism (E84E 20.5%) and one novel missense mutation (Y424H 1.2%). Segregation analysis of the I157T and S428F mutations (shown to affect protein function) with the cancer phenotype showed concordance for the CHK2*I157T mutation, as did two of three families with the CHK2*S428F mutation.

Conclusions: CHEK2 missense mutations may contribute to breast cancer susceptibility in Ashkenazi Jews.

Background: In developed countries, the incidence of Sydenham’s chorea, a major sign of rheumatic fever has declined, but outbreaks are still encountered worldwide.

Objectives: To report the characteristics of a cohort of SC[1] patients in the Jerusalem area.

Methods: We conducted a prospective assessment of rheumatic fever and SC between 1985 and 2002. The diagnosis of rheumatic fever was based on the revised Jones criteria. Other etiologies of chorea were excluded. Recurrence was defined as the development of new signs, lasting more than 24 hours and separated by a minimum of 2 months from the previous episode. Patients were followed for 1 to 14 years following the initial SC episode, and at least one year after recurrence.

Results: Among 180 children with rheumatic fever, 24 had SC. Most of them came from large families of Ashkenazi origin. In 19 patients (79%) the chorea was associated with other rheumatic fever signs, while 5 had pure chorea. Due to the systematic use of two-dimensional color Doppler echocardiography, cardiac involvement was detected in 75% of the patients. Ten patients (42%, 7 females) developed 11 recurrent episodes of chorea 3 months to 10 years after the initial episode. At recurrence, chorea was the sole rheumatic sign in all nine patients who recurred once. None of the patients had persistent chorea.

Conclusions: SC is still prevalent in the pediatric population of Jerusalem, and may recur years later. Recognition of the disease and adequate treatment is necessary.

Background: Recent genetic susceptibility findings in Jews of Eastern European descent, commonly called Ashke­nazi Jews, have led to concerns that they may be stigmatized as being more cancer prone than other groups.

Objective: To examine the hypothesis that site-specific or all-cancer incidence and mortality rates are higher than expected in Ashkenazi Jews worldwide when compared with referent populations.

Methods: A MEDLINE search was performed using keywords "Jews", "cancer", "incidence" and "mortality" to identify studies directly relevant to the primary study question.

Results: Little evidence suggested that all-cancer inci­dence or mortality is higher in Ashkenazi Jews than in North American non-Hispanic whites. Ashkenazi Jewish men appear to have relatively low cancer rates, which may be due to lower tobacco use. Colorectal cancer was shown to disproportio­nately overburden Ashkenazi Jews, who may also be at increased risk for ovarian, pancreatic and stomach cancer, and non-Hodgkin’s lymphoma. Little evidence was found support­ing an elevated risk of breast cancer in Ashkenazi Jewish women. Rates of lung, cervical, penile and prostate cancers appear low in this population. Rate disparities were generally attributed to lifestyle differences, particularly diet and tobacco use, rather than to genetic predisposition.

Conclusions: Ashkenazi Jews do not appear to have a higher total cancer burden than comparable North American populations. Any cancer rate differentials in this group are more likely to be related to lifestyle and dietary factors than to genetics. However, colorectal cancer rates in Ashkenazi Jews may be the highest of any ethnic group in the world and cancer controllers should consider this when developing future screening, diagnostic and policy strategies.