Prevalence of microdeletion 22q11 in patients with hypernasal speech due to velopharyngeal insufficiency: Expanded phenotype and clinical comparison to nondeletion
- Univ. of Toronto, Ontario (Canada)
Microdeletion 22q11.2 has been reported as a frequent ethiology of both velocardiofacial (VCF) and DiGeorge syndromes. We have studied the prevalence of microdeletion 22q11 in a group of patients ascertained through a Speech and Language clinic presenting with (1) velopharyngeal insufficiency (VPI) and (2) difficultly in school. Growth parameters were measured, and facies were scored for features of VCF. Microdeletions were detected at locus D22S75 by FISH with probe N25 (Oncor), and at 22q11.2 with high resolution banding analysis (HRB). One child with typical VCF facies was considered to have a deletion at 22q11 with HRB, but is not deleted with N25, indicating that N25 may not detect all deletion patients. An additional 8/30 children tested to date were deleted with the N25 probe. Heart defects were present in only 2/8 deletion patients: VSD/ASD and PS/AS. One N25 deletion patient was atypica; he has a tall, lanky habitus (height = 90%), and facies not characteristic of CVF. As expected, there is a trend to lower head size, smaller ear size, and more typical facies in deletion patients; however, four of the nondeletion patients also had a clinical diagnosis of VCF. Medially displaced carotid arteries were present in both groups, which is therefore not a diagnostic feature of microdeletion 22q11. Our findings indicate that the microdeletion 22q11 is frequent (26% in this series) in a population with VPI, even when not selected for typical facies. We believe this series supports the view that microdeletion 22q11 has a broader clinical phenotype than previously recognized.
- OSTI ID:
- 133758
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-0490
- Journal Information:
- American Journal of Human Genetics, Vol. 55, Issue Suppl.3; Conference: 44. annual meeting of the American Society of Human Genetics, Montreal (Canada), 18-22 Oct 1994; Other Information: PBD: Sep 1994
- Country of Publication:
- United States
- Language:
- English
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