Familial Glucocorticoid Deficiency in Twins: A Novel Mutation and Impact on Social Determinants of Health Outcome.

Familial glucocorticoid deficiency (FGD) is a rare autosomal recessive disorder that causes isolated glucocorticoid deficiency. Here, we report on 22-month-old twin females of Native American ancestry who presented within 1 week of each other in adrenal crisis and were ultimately diagnosed with FGD because of a novel pathogenic variant, c1924G>T (p. Gly642*), in the nicotinamide nucleotide transhydrogenase (NNT) gene. This is the first report of FGD in a Native American population. The process of reaching the final diagnosis was complicated by several social determinants including geographic rurality, access to subspecialists, financial constraints, and challenges obtaining approval for genetic testing despite having insurance. Concerted efforts by the family, the local pediatrician, the Indian Health Service, and our tertiary care pediatric health system were required to reach the final diagnosis and develop an appropriate plan of care for the patients.