Molekular-zytogenetische Charakterisierung komplexer, struktureller Chromosomenaberrationen bei einer Patientin mit schwerer mentaler Retardierung, chronischer Polyarthritis und physischen Dysmorphien
LicenseStandard (Fassung vom 01.10.2008)
This work reports on a patient with severe mental retardation, dysmorphic features as well as juvenile idiopathic arthritis. G-banding indicated two independent karyotypic anomalies in this patient: an interstitial deletion del(X)(p21p22.3) and a rearrangement involving the chromosomes 1 and 7 which represents a direct insertion, ins(7;1)(q36;p13.2p31.2). Non-random inactivation of the paternally derived del(X) chromosome was observed in blood lymphocytes and fibroblasts. High resolution analysis of the rearrangement involving the chromosomes 1 and 7 subsequently revealed the additional submicroscopic deletion of at least 5.1 Mb at the 1p13.2 breakpoint. The deletion occurred on the paternal chromosome and encompasses the PTPN22 gene, already known to be associated with juvenile idiopathic arthritis. My findings underline the importance of closely investigating the breakpoint regions of apparently balanced rearrangements in patients with abnormal phenotypes since complex chromosomal rearrangements may turn out to be unbalanced.
Subject HeadingsChromosomenaberration [GND]
Protein tyrosine phosphatase, non-receptor type 22 [MeSH]