As shown in a study examining the genotype-to-protein-to-phenotype of SSADHD, worst severity was associated with lacking or a truncated SSADH (as opposed to having a SSADH composed of single homotetramers or multiple homo and heterotetramers), as well as having functional impairments in the enzyme’s catalytic functions (as opposed to stability, folding, or oligomerization) [22]. The gene discussed is ALDH5A1; the disease is succinic semialdehyde dehydrogenase deficiency.