GCDH and glutaryl-CoA dehydrogenase deficiency: However, controversy persists con­cerning attempts to connect phenotype to specific genotypic markers of the disease, as patients symptomatic for GA1 sometimes do not present with GCDH deficiency (Westover et al., 2003 ▶; Christensen et al., 2004 ▶; Garcia et al., 2008 ▶).