First case of Hajdu-Cheney syndrome in Lithuania caused by novel NOTCH2 gene likely pathogenic variant.

Hajdu-Cheney syndrome (HCS) is an extremely rare autosomal dominant skeletal disorder. The prevalence rate of less than 1 case per 1,000,000 newborns and only 50 cases were reported in the medical literature. HCS is characterized by progressive bone resorption in the distal phalanges (acro-osteolysis), progressive osteoporosis, distinct craniofacial changes, dental anomalies, and occasional association with renal abnormalities. HCS is caused by pathogenic variants in the NOTCH2 gene, 34th exon. We report first familial case of HCS caused by likely pathogenic variant of NOTCH2 gene c.6449delC, p.(Pro2150LeufsTer5).