title: Expanding the phenotypic and mutational spectrum in microcephalic osteodysplastic primordial dwarfism type I.
abstract: Mutations in the RNU4ATAC gene cause microcephalic osteodysplastic primordial dwarfism type I. It encodes U4atac, a small nuclear RNA that is a component of the minor spliceosome. Six distinct mutations in 30 patients diagnosed as microcephalic osteodysplastic primordial dwarfism type I have been described. We report on three additional patients from two unrelated families presenting with a milder phenotype of microcephalic osteodysplastic primordial dwarfism type I and metopic synostosis. Patient 1 had two novel heterozygous mutations in the 3' prime stem-loop, g.66G > C and g.124G > A while Patients 2 and 3 had a homozygous mutation g.55G > A in the 5' prime stem-loop. Although they manifested the known spectrum of clinical features of microcephalic osteodysplastic primordial dwarfism type I, they lacked evidence of severe developmental delay and neurological symptoms. These findings expand the mutational and phenotypic spectrum of this syndrome.
authors.affiliation: Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt. ghada.abdelsalam@yahoo.com
authors.forename: Ghada M H
authors.initials: GM
authors.lastname: Abdel-Salam
authors.forename: Mohamed S
authors.initials: MS
authors.lastname: Abdel-Hamid
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Issa
authors.forename: Ahmed
authors.initials: A
authors.lastname: Magdy
authors.forename: Ahmed
authors.initials: A
authors.lastname: El-Kotoury
authors.forename: Khalda
authors.initials: K
authors.lastname: Amr
mesh_terms: D000015:Abnormalities, Multiple / Q000175:diagnosis / Q000235:genetics; D004392:Dwarfism / Q000175:diagnosis* / Q000235:genetics*; D019066:Facies; D005260:Female; D005317:Fetal Growth Retardation / Q000175:diagnosis* / Q000235:genetics*; D006801:Humans; D007223:Infant; D017880:Limb Deformities, Congenital / Q000000981:diagnostic imaging; D008297:Male; D008831:Microcephaly / Q000175:diagnosis* / Q000235:genetics*; D009154:Mutation; D059906:Neuroimaging; D010009:Osteochondrodysplasias / Q000175:diagnosis* / Q000235:genetics*; D010388:Pelvis / Q000000981:diagnostic imaging; D010641:Phenotype; D012342:RNA, Small Nuclear / Q000235:genetics*; D011859:Radiography
chemical_list: D012342:RNA, Small Nuclear