We estimate 0.5 affected birth every year for glutaric aciduria IIC disease and congenital myasthenic syndrome, 1.5 per year for sialic acid storage disorder, 1.8 for autoimmune polyendocrinopathy syndrome type I and up to 9 per year for Butyrylcholinesterase deficiency if both parents are ethnic Acadians (Table 1). The gene discussed is BCHE; the disease is congenital myasthenic syndrome.