Fifth, reverse phenotyping contributed to five cases: brain MRI review was in keeping with the CNS phenotype exhibited by Patient G (Fig. 3b) and Patient C (Fig. 2c); skeletal survey and updated clinical history suggested a mild variant of Hall-type spondyloepimetaphysial dysplasia with joint laxity (Fig. 3c, Patient R); muscle biopsy supported the pathogenicity of a mosaic variant in DNM2 (Fig. 3d panel (i), Patient I) and compound heterozygous variants in MYH2 in Patient E [Fig. 2a panel (ii)]; and Patient O dysmorphology was in keeping with a mild variant of Feingold syndrome type 1. The gene discussed is MYH2; the disease is Feingold syndrome type 1.