PRKG2 and spondylometaphyseal dysplasia: Therefore, the description of this now confirmed Mendelian condition constitutes an additional example of rare variants in a gene causing a severe condition, where common variants in the same gene are associated with a related trait.10 In summary, analysis of 100KGP data combined with gene-matching efforts identified four affected individuals with biallelic loss of function variants in PRKG2, extending the phenotypic range of this condition to include spondylometaphyseal dysplasia.