Israel Medical Association Journal

Background: Reduced sensitivity to thyroid hormone (RSTH) syndrome describes a group of rare heterogeneous genetic disorders. Precise diagnosis is essential to avoid unnecessary treatment.

Objectives: To identify and characterize previously undiagnosed patients with RSTH in Israel.

Methods: Patients with suspected RSTH throughout Israel were referred for study. After clinical evaluation, genomic DNA was obtained and all coding exons of the thyroid hormone receptor beta (THRB) gene were sequenced. If mutations were found, all available blood relatives were evaluated. The common polymorphism rs2596623, a putative intronic regulatory variant, was also genotyped. Genotype/phenotype correlations were sought, and the effect of mutation status on pregnancy outcome was determined.

Results: Eight mutations (one novel; two de-novo, six dominant) were identified in eight probands and 13 family members. Clinical and genetic features were similar to those reported in other populations. Previous suggestions that rs2596623 predicts clinical features were not confirmed. There was no evidence of increased risk of miscarriage or fetal viability. Mothers carrying a THRB mutation tended to have increased gestational hypertension and low weight gain during pregnancy. Their affected offspring had increased risk of small-for-gestational age and poor postnatal weight gain.

Conclusions: Clinical heterogeneity due to THRB mutations cannot be explained by the variant rs2596623. Mothers and newborns with THRB mutations seem to be at increased risk of certain complications, such as gestational hypertension and poor intrauterine and postnatal growth. However, these issues are usually mild, suggesting that routine intervention to regulate thyroid hormone levels may not be warranted in these patients.

Background: Sickle cell anemia is a hemolytic anemia caused by a single mutation in position 6 of the β globin molecule. About 80 patients with SCA[1] in northern Israel are currently receiving treatment.

Objectives: To assess a screening program in northern Israel aimed at detecting couples at risk for having offspring with SCA.

Methods: Since 1987, screening for β thalassemia in pregnant women in northern Israel has been conducted, and from 1999 all the samples were also tested for hemoglobin S, Hgb C, Hgb D, Hgb O Arab and others.

Results: During the 20 year period 1987–2006 a total of 69,340 women were screened; 114 couples who carried Hgb S were detected and 187 prenatal diagnoses were performed in couples at risk for having an offspring with Hgb S. The mean gestational age was 13 ± 4 weeks. Fifty-four of those diagnoses revealed affected fetuses and in 4 cases the couple declined to perform therapeutic abortion.

Conclusions: The economic burden to the health services for treating SCA patients is about U.S.$ 7000 per year, and the institution of prevention programs has proven cost-effective in populations with a high frequency of carriers. Since our program is aimed to also detect β thalassemia, a disease that is more frequent in this area (> 2.5%), the added cost for the prevention of SCA is less significant in spite a low incidence of the S gene in our population, namely < 1%.