Four sibs, three males and one female, had microcephaly, hypergonadotropic hypogonadism, short stature, and multiple congenital anomalies. They had five normal sibs and consanguineous parents. Findings in the affected sibs also included a narrow forehead, synophrys, micrognathia, abnormally folded pinnae, early loss of teeth in three, cubitus valgus in two, genu valgum, gynecomastia, and undescended testes in one. All sibs had normal chromosomes. Results of tests for growth hormone release and adrenocortical function were normal. Luteinizing hormone releasing hormone (LHRH) and human chorionic gonadotropin (hCG) stimulation tests were consistent with primary gonadal failure. Testicular biopsy, performed on two affected males, was normal in one and showed focal atrophy with decreased spermatogenesis in the other. The patients manifest a phenotype different from all other known types of hypergonadotropic hypogonadism and appear to represent a new MCA/MR syndrome.