Fig. 1.

Clinical features and genetic analysis. a Pedigree and a homozygous and heterozygous variants in RNASEH2B. b Physical examinations and imaging findings showing deformed inter-phalangeal joints (B1), chilblains (B2), short statue (B3), synovial thickening(B4), cerebral atrophy and white matter abnormalities (B6), calcifications in basal ganglia and cerebellum (B5 and B7). c Renal biopsy findings (10 × 20) showing glomerular sclerosis, a mild proliferation of mesangial cells, infiltration of lymphocytes and other mononuclear cells