Glycogen Storage Disease Type Ia (GSDIa) is characterized by accumulation of glycogen and fat in the liver and kidneys. Long-term complications of untreated GSDIa include growth retardation and resulting short stature, delayed puberty, gout, renal disease, pulmonary hypertension and changes in brain function. Normal growth and puberty may be expected in treated children, and many affected individuals live into adulthood. It is an autosomal recessive disorder caused by mutations in the G6PC gene. It occurs more frequently in the Ashkenazi Jewish population, where the carrier rate is 1 in 71. Ashkenazi Jewish individuals with a negative family history who test negative for the R83C and Q347X mutations in G6PC have a revised carrier risk of 1 in 7,000.