[MIM 251 260]

(AT V1, ataxia-telangiectasia Variant 1, NBS, Berlin breakage syndrome, Nijmegen breakage syndrome, Seemanova type 2 syndrome)

Rare but prevalence is greater in groups from Central and Eastern Europe: Czech Republic, Poland, Russia, Ukraine. Autosomal recessive transmission of a mutation of the NBN gene on 8q21-q24, which codes for nibrine, a protein which, forming a trimeric complex protein  with MRE11 and RAD50 called MNR, is involved in the repair of double-stranded DNA injuries.

Clinical presentation:

-        microcephaly: present from birth (< 2 SD of the average), which worsens with age and is accompanied by mental retardation and a delay in acquisition of speech

-        facial dysmorphism: receding chin,  sloping forehead, emaciated face, up- an backslanting palpebral fissures; the nose is long and hooked, or short with anteverted nostrils

-        moderate stunting  with hypergonadotrophic hypogonadism in girls

-        cellular and humoral immunodeficiency: frequent infections, especially of the respiratory tract

-        increased risk of tumors and hematologic diseases: 40 % of patients develop a malignant disease before the age of 20 years: the most commons are of lymphoid origin: non-Hodgkin's lymphoma, T-cell lymphoblastic lymphoma, more rarely Burkitt Lymphoma; myelosuppression, medulloblastoma, rhabdomyosarcoma

Sometimes:

-        cleft palate, choanal atresia

-        clinodactyly of the 5th fingers, partial syndactyly of the fingers; sometimes polydactyly

-        urogenital anomalies: renal hypoplasia, dystrophy or aplasia, horseshoe kidney, hypospadias

-        Cafe au lait spots and/or patches of vitiligo.

-        thin and sparse hair in children and early graying (around the age of 20-30 years)

-        hypoplasia or aplasia of the Corpus Callosum

Anesthetic implications:

check blood count and renal function, pulmonary auscultation (bronchiectasis ?), risk of difficult intubation, high sensitivity to the carcinogenic effects of X-rays (radiation protection)

References:

-         Chrzanowska KH, Gregorek H, Dembowska-baginska B, Kalina MA, Digweed M. 
Nijmegen breakage syndrome (NBS). 
Orphanet J Rare Diseases 2012 ; 7 :13.

Updated: November 2018