Interestingly, both mutations and similar deletions of SOX5 have previously been described in Lamb-Schaffer syndrome (MIM 616803), an autosomal dominant syndrome with varying phenotypes including ONH, optic atrophy (MIM 165500), developmental delay, behavioural problems, poor expressive speech, mild dysmorphic features, and skeletal abnormalities [30,31]. The gene discussed is SOX5; the disease is Global developmental delay.