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Home > D. General pathology > Genetic and developmental anomalies > Chromosomal diseases > Microdeletion syndromes > del(22)(q11.2)


Sunday 18 December 2005

Deletion 22q11.2 syndrome is the most frequent known microdeletion syndrome and is associated with a highly variable phenotype, including DiGeorge and Shprintzen (velocardiofacial) syndromes.

Although haploinsufficiency of the T-box transcription factor gene TBX1 is thought to cause the phenotype, to date, only four different point mutations in TBX1 have been reported in association with six of the major features of 22q11.2 deletion syndrome.

Although, for the two truncating mutations, loss of function was previously shown, the pathomechanism of the missense mutations remains unknown.

Synopsis (exemples)

- deletion 22q11.2 syndrome (D22S)
- Di George syndrome
- Tetralogy of Fallot
- developmental delay
- neural tube defects (NTDs)

- velo-cardio-facial syndrome
- DiGeorge sequence
- congenital heart defect
- minor facial anomalies
- thymic hypoplasia
- cleft lip and/or cleft palate
- hypocalcemia
- conotruncal heart defect

- parathyroid gland dysfunction (16793949)

See also

- constitutional deletions