Study of Phenotype and Genotype Correlations in Patients With Contiguous Gene Deletion Syndromes

Overview

OBJECTIVES: I. Investigate phenotype and genotype correlations in patients with Smith-Magenis syndrome (SMS) associated with del(17p11.2). II. Clinically evaluate SMS patients with unusual deletions or duplication of proximal 17p. III. Clinically evaluate patients with Williams syndrome with molecular characterization of 7q11.23. IV. Perform clinical studies of Prader-Willi, Angelman, DiGeorge, and Shprintzen syndrome patients with unique molecular findings in 15q11q13 or 22q11.2. V. Perform genotype and phenotype correlations in Prader-Willi patients, particularly those with loss of expression of only some of the imprinted transcripts in 15q11-q13. VI. Evaluate putative Angelman syndrome patients who do not have classic large deletion, uniparental disomy, or imprinting mutations, and perform molecular studies of the Angelman gene, UBE3A, and identify mutations of this gene. VII. Investigate phenotype and genotype correlations in patients with terminal deletions of chromosome 1p.

PROTOCOL OUTLINE: Patients undergo clinical, cytogenetic, and molecular studies. These include radiographic, neurologic, developmental, and 24 hour sleep studies, ophthalmologic, otolaryngologic, speech and language, and audiologic exams, echocardiogram, and renal ultrasound. Smith-Magenis patients are also evaluated with the following: urine melatonin levels during day and night hours; anthropometrics; sleep and behavioral history; and renal, immunologic, and cholesterol studies. A clinical and phenotypic map is constructed. When appropriate, parental chromosome analysis is performed.

Conditions