MedGen

Nijmegen breakage syndrome (NBS) is characterized by progressive microcephaly, early growth deficiency that improves with age, recurrent respiratory infections, an increased risk for malignancy (primarily lymphoma), and premature ovarian failure in females. Developmental milestones are attained at the usual time during the first year; however, borderline delays in development and hyperactivity may be observed in early childhood. Intellectual abilities tend to decline over time. Recurrent pneumonia and bronchitis may result in respiratory failure and early death. Other reported malignancies include solid tumors (e.g., medulloblastoma, glioma, rhabdomyosarcoma). [from GeneReviews]

The hereditary hyperbilirubinemias include (1) those resulting in predominantly unconjugated hyperbilirubinemia: Gilbert or Arias syndrome, Crigler-Najjar syndrome type I (218800), and Crigler-Najjar syndrome type II (606785); and (2) those resulting in predominantly conjugated hyperbilirubinemia: Dubin-Johnson syndrome (237500), Rotor syndrome (237450), and several forms of intrahepatic cholestasis (147480, 211600, 214950, 243300) (Wolkoff et al., 1983). Detailed studies show that patients with Gilbert syndrome have reduced activity of bilirubin glucuronosyltransferase (Bosma et al., 1995, Koiwai et al., 1995). Genetic Heterogeneity of Hyperbilirubinemia See also Crigler-Najjar syndrome type I (HBLRCN1; 218800), Crigler-Najjar syndrome type II (HBLRCN2; 606785), and transient familial neonatal hyperbilirubinemia (HBLRTFN; 237900), all caused by mutation in the UGT1A1 gene (191740) on chromosome 2q37; Dubin-Johnson syndrome (DJS, HBLRDJ; 237500), caused by mutation in the ABCC2 gene (601107) on chromosome 10q24; and Rotor syndrome (HBLRR; 237450), caused by digenic mutation in the SLCO1B1 (604843) and SLCOB3 (605495) genes, both on chromosome 12p. [from OMIM]