GLDC and metabolic disease: Extremely small homozygous pathogenic deletions were identified in two cases: 1): a new born baby girl who presented with a metabolic disorder (abnormal reflexes, hypotonia, seizures, and elevated glycine) was revealed to contain a 25-kb homozygous deletion in the GLDC gene, which gave rise to autosomal recessive glycine encephalopathy (nonketotic hyperglycinemia; OMIM #605899).