An inborn error of proline/orinthine metabolism that covers a wide spectrum of phenotypes and is caused by pathogenic variants in the aldehyde dehydrogenase 18 family member A1 (ALDH18A1) gene. These variants lead to a variety of neurocutaneous and motor syndromes characterized by cutis laxa, connective tissue weakness, facial dysmorphism, growth restriction, developmental delay, cataracts, hypotonia, hypertonia, and amyotrophy. [ http://www.ncbi.nlm.nih.gov/pubmed/32017139 ]