Israel Medical Association Journal

Illicit drug abuse is a widespread medical problem with numerous sequelae. One of the major challenges in reaching a diagnosis is the difficulty in obtaining accurate details during the medical interview. We describe a patient who initially denied drug abuse while presenting a bizarre nasopharyngeal disease secondary to inhalation of oxycodone-acetaminophen powder.

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: Primary pulmonary hypertension is a rare disorder, characterized by progressive pulmonary hypertension and right heart failure. It may be familial or sporadic. Mutations in bone morphogenetic protein receptor II (BMPR2), a member of the transforming growth factor-beta receptor superfamily of receptors, underlie many cases of the disorder.

Objectives: To perform molecular analysis of a patient with familial PPH[1] and provide her and her family with suitable genetic counseling.

Methods: DNA was extracted from 10 ml whole blood, and the BMPR2 gene was screened for mutations. Individual exons were amplified by polymerase chain reaction and sequenced. Mutation confirmation and molecular characterization of additional family members was performed using restriction enzyme analysis followed by appropriate genetic counseling.

Results: We identified a novel T to C missense mutation expected to result in substitution of arginine for a conserved cysteine in the ligand-binding domain of BMPR2. Screening of family members demonstrated the presence of the mutation in the father and a younger asymptomatic sister of the index patient.

Conclusions: Molecular diagnosis in PPH allows for identification of at-risk family members and raises the option of earlier diagnosis and possibly instituting earlier treatment in affected individuals. However, molecular screening of asymptomatic family members raises difficult ethical questions that can only be resolved by conducting large multicenter prospective studies in BMPR2 carriers.