analysis molecular genetics English

22Q11 DELETION SYNDROME

OMIM: 188400, 192430
Diagnostic method:

MLPA

Samples required:

2 ml EDTA blood

Duration of analysis: 1 week
Forms:  

A deletion in the chromosomal region 22q11 is often found in patients with congenital heart defects (typically conotruncal defects). It is the genetic basis not only of the DiGeorge and velocardiofacial syndrome, but also of numerous and varied other phenotypes. In about 1 % of sporadic heart defects, there is a deletion 22q11.

Besides the known heart defects (defects of the right or left outflow tract as well as the large arteries such as interrupted aortic arch (type B), truncus arteriosus communis, tetralogy of Fallot, ventricular septal defects (VSD) associated with other anomalies, double outlet right ventricle and pulmonary atresia with VSD, vascular anomalies such as right aortic arch or arteria lusoria), ORL anomalies, psychomotor retardation and characteristic dysmorphic signs, these patients may exhibit a variety of other clinical pathologies. The incidence of deletion 22q11 is 1/5,000 births, or 5 % of all newborns with a heart vitium have deletion 22q11. This makes it the second most common known genetic cause of congenital heart defects after trisomy 21. The majority of deletions 22q11 arises de novo. A familial form is found in 8 to 28 % of patients. The inheritance is autosomal dominant.

The phenotypic spectrum of deletion 22q11 is very broad: 180 different clinical manifestations are described. Heart defects, ORL anomalies, facial dysmorphia and psychomotor retardation are the most common clinical symptoms. 14 % of all patients with deletion 22q11 have a cleft palate. Since deletions in the areas 10p14, 8q23, 18q21, 17p13, 4q21-25, 4q34 are also associated with symptoms of DiGeorge syndrome, they are included in the study.

Indication:

  • suspicion of velocardiofacial syndrome
  • congenital heart defect

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