Any developmental delay with short stature, dysmorphic facial features, and sparse hair in which the cause of the disease is a mutation in the DPH1 gene. The disease is developmental delay with short stature, dysmorphic facial features, and sparse hair 1 (Monarch Disease Ontology term MONDO_0800438). Also known as: DEDSSH1, developmental delay with short stature, dysmorphic features, and sparse hair 1, diphtamide deficiency syndrome.