Expanding phenotype of XNP mutations: mild to moderate mental retardation.
Mutations in the XNP gene have been reported in alpha thalassemia/mental retardation (MR) syndrome (ATR-X) and other severe X-linked MR conditions with facial dysmorphisms. In this report, we describe a missense mutation in exon 18 in a family with borderline to moderate MR. Like other disorders associated with an XNP mutation, skewed X-inactivation was found in all carrier females in this family. Only retrospective examination revealed childhood facial hypotonia and HbH inclusions in some of the affected males. These results expand the spectrum of clinical phenotypes known to be due to mutations in the XNP gene, and indicate that XNP mutation analysis should not be restricted to patients with severe MR and characteristic facial features.
Department of Human Genetics, University Medical Centre, Nijmegen, The Netherlands.
Helger G
HG
Yntema
Francis A
FA
Poppelaars
Esther
E
Derksen
Astrid R
AR
Oudakker
Tanja
T
van Roosmalen
Anja
A
Jacobs
Hanneke
H
Obbema
Han G
HG
Brunner
Ben C J
BC
Hamel
Hans
H
van Bokhoven
D000328:Adult; D000368:Aged; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004265:DNA Helicases; D004252:DNA Mutational Analysis; D005192:Family Health; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D020125:Mutation, Missense; D009687:Nuclear Proteins / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype; D000075924:X-linked Nuclear Protein
D009687:Nuclear Proteins; D004247:DNA; D004265:DNA Helicases; C092332:ATRX protein, human; D000075924:X-linked Nuclear Protein