X-linked mental retardation
| Classification according to ICD-10 | |
|---|---|
| Q87.8 | Other specified congenital malformation syndromes, not elsewhere classified |
| ICD-10 online (WHO version 2019) | |
The X-linked mental retardation (XLMR) is 5-18%, the most common form of genetic mental retardation .
Synonyms are: X-linked intellectual disability; Mental retardation, X-linked; English X-linked Mental Retardation; XLMR
distribution
The frequency is estimated at 1 in 600 or 1 in 1,000 men. Because of the X-linked inheritance, the male sex is affected significantly more.
root cause
There are now more than 200 known genes whose mutation is involved in XLMR.
Classification
A distinction is made clinically:
- Fragile X syndrome (about 15-20%)
- Nonsyndromic X-linked mental retardation (MRX) without additional abnormalities (about 66%)
- Syndromic X-linked mental retardation (S-XLMR, MRXS) with additional changes (rare)
In addition, X-linked mental retardation is a feature of some syndromes that are not classified as S-XLMR:
- ATR-X syndrome
- Börjeson-Forssman-Lehmann syndrome
- Coffin-Lowry Syndrome
- MASA syndrome
- Lujan-Fryns Syndrome
- Prieto syndrome
- Snyder-Robinson Syndrome
Clinical manifestations and diagnosis
The main symptom is the intellectual disability, clinically no other abnormalities are evident. A family history of possible X-linked inheritance is essential.
Individual evidence
- ↑ a b MGZ Munich
- ↑ a b c intellectual disability, nonsyndromic, X-linked. In: Orphanet (Rare Disease Database).
- ^ A b P. Chiurazzi, CE Schwartz, J. Gecz, G. Neri: XLMR genes: update 2007. In: European journal of human genetics: EJHG. Vol. 16, No. 4, April 2008, pp. 422-434, doi: 10.1038 / sj.ejhg. 5201994 , PMID 18197188 (Review).
- ↑ P. Chiurazzi, E. Tabolacci, G. Neri: X-linked mental retardation (XLMR): from clinical conditions to cloned genes. In: Critical reviews in clinical laboratory sciences. Vol. 41, No. 2, 2004, pp. 117-158, doi: 10.1080 / 10408360490443013 , PMID 15270552 (review).
