OBJECTIVEInactivating mutations of DAX-1 give rise to the X-linked form of adrenal hypoplasia congenita (AHC). Affected individuals are at risk of early postnatal Addisonian crisis, but the variable phenotypic expression of DAX-1 insufficiency renders this diagnosis challenging. This study aimed to understand the clinical features and identify DAX-1 gene mutation of the affected individuals and their relatives in a Chinese adrenal hypoplasia congenita kindred.

METHODSThe proband was diagnosed as adrenal insufficiency shortly after birth and his elder cousin was also diagnosed as having this disease at the age of about 8 years. Clinical data were obtained from 2 affected individuals when they were hospitalized into the department of pediatrics, Ruijin Hospital in 2006; 20 peripheral blood samples were obtained from the affected individuals and their relatives; exons in DAX-1 gene were amplified, and PCR product was purified and sequenced directly for analyzing mutation.

RESULTSA novel hemizygous mutation (T785C) was found in DAX-1 gene in both patients. Some clinical features such as the age of onset were different although these 2 patients carried the same mutation. There were 5 carriers of this mutation in the patients' maternal pedigree.

CONCLUSIONThe results suggested that adrenal hypoplasia congenita in this kindred was caused by a novel mutation (T785C) in DAX-1 gene, and the same mutation can give rise to the variable phenotype.