N syndrome
| Classification according to ICD-10 | |
|---|---|
| Q87.8 | Other specified congenital malformation syndromes, not elsewhere classified |
| ICD-10 online (WHO version 2019) | |
The N-Syndrome is a very rare congenital malformation syndrome with the main characteristics of intellectual disability , hearing impairment , eye problems , cryptorchidism , hypospadias and tetraspasticity .
Synonyms are: NSX, Opitz N syndrome
The first description comes from 1970 by the German-American human geneticist John Marius Opitz .
It was named after the first letter of the family described.
distribution
The frequency is given as less than 1 in 1,000,000, inheritance is X-linked - recessive .
root cause
The disease are mutations in POLA1 - gene on locus Xp22.1-p21.3 based encoding the DNA polymerase alpha.
Clinical manifestations
Clinical criteria are:
- pronounced intellectual disability
- Growth retardation, evident from the age of the bones
- central vision disorders
- deafness
- Facial abnormalities such as dolichocephaly , hypotelorism , externally overlapping eyelids , megalocornea , dysplasia of the auricles , misaligned teeth
- general skeletal dysplasia with excessive bone formation in the long bones and shortening distally
- Cryptorchidism, hypospadias
literature
- KM Floy, RO Hess, LF Meisner: DNA polymerase alpha defect in the N syndrome. In: American journal of medical genetics. Vol. 35, No. 3, March 1990, pp. 301-305, doi: 10.1002 / ajmg.1320350302 , PMID 1689958 .
- RO Hess, EG Kaveggia, JM Opitz: Studies of malformation syndromes in man. XXVII. The N syndrome, a "new" multiple congenital anomaly-mental retardation syndrome. In: Clinical genetics. Vol. 6, No. 4, 1974, pp. 237-246, PMID 4216437 .
Individual evidence
- ↑ a b Bernfried Leiber (founder): The clinical syndromes. Syndromes, sequences and symptom complexes . Ed .: G. Burg, J. Kunze, D. Pongratz, PG Scheurlen, A. Schinzel, J. Spranger. 7., completely reworked. Edition. tape 2 : symptoms . Urban & Schwarzenberg, Munich et al. 1990, ISBN 3-541-01727-9 .
- ↑ a b c Orphanet
- ↑ POLA1. In: Online Mendelian Inheritance in Man . (English)
