Table 3

Comparison of NBS with Bloom syndrome (BS) and ataxia telangiectasia (AT)

NBS BS AT
Gene locus8q2115q2611q22–23
GeneNBS1BLMATM
Microcephaly++++
Growth retardation++++±
Mental retardation±±
Typical facial appearance++
Telangiectasia
Ocular±++
 Cutaneous±+++
Skin abnormalities
Hyperpigmentation+++
 Sunlight sensitivity+++
 Cerebellar ataxia++
 Recurrent infections++±++
 Elevated α fetoprotein levels++
 Immunodeficiency++++
 Cancer predisposition+++++
 Chromosomal instability++++++
 Radiation hypersensitivity++++
  • −, absent; ±, rare; +, usual; ++, frequent.