Developmental delay with short stature, dysmorphic features and sparse hair (DEDSSH) (MIM # 616901) is an ultra-rare, neurodevelopmental disorder caused by biallelic pathogenic or likely pathogenic variants in the DPH1 gene, mapped to chromosome 17p13.3.
Main clinical features
It is characterized by variable degree of intellectual disability (moderate to profound), short stature, hand/ foot anomalies, unusual head shape/, dysmorphic features, and ectodermal anomalies.
Prevalence
It is an ultra-rare condition. The exact prevalence is unknown. To date, less than 30 affected individuals and foetuses have been reported (Alazami et al. (2015); Cheng et al. (2021); Hao et al. (2021); Lefebvre et al. (2021); Monies et al. (2019); Nakajima et al. (2018); Powis et al. (2018); Riazuddin et al. (2020); Sekiguchi et al. (2018); Shamseldin et al. (2021); Urreizti et al. (2020)). Most reported individuals were children, some even had early lethality.
Inheritance
The disorder is inherited in an autosomal recessive manner. Parental consanguinity is present in majority of affected families. Usually, parents are heterozygous carriers of variants in the DPH1 gene.
DPH1