Author/Editor		Erjavec-Škerget, Alenka; Stangler-Herodež, Špela; Zagorac, Andreja; Zagradišnik, Boris; Kokalj-Vokač, Nadja
Title		New molecular - cytogenetic techniques for screening patients with idiopathic mental retardation
Translated title		Nove molekularne citogenetske tehnike za presejanje bolnikov z idiopatsko duševno manjrazvitostjo
Type		članek
Source		In: Luzar B, Poljak M, Glavač D, et al, editors. Molekularna diagnostika v medicini. Zbornik 15. spominsko srečanje akademika Janeza Milčinskega, 36. memorialni sestanek profesorja Janeza Plečnika, 1. srečanje Slovenskega društva za humano genetiko z mednarodno udeležbo; 2005 30 nov - 2 dec; Ljubljana. Ljubljana: Medicinska fakulteta,
Publication year		2005
Volume		str. 303-8
Language		eng
Abstract		Subtelomeric rearrangements are a common cause of idiopathic mental retardation (IMR). Due to the development of molecular-cytogenetic techniques, it is now possible to identify cryptic rearrangements involving the ends of chromosomes. The screening method generally used for detection of subtelomeric rearrangements is multiprobe telomere fluorescent in situ hybridization (T-FISH). Specific T-FISH probes, multiplex ligation-dependent probe amplification (MLPA) and comparative genomic hybridization (CGH) were used to screen 81 patients (children and young adults, 0-21-years old) with MR and dysmorphic features. T-FISH revealed subtelomeric abnormalities in 8 patients (9.8%). Three of these only had a deletion of subtelomeric 2q, which was apparently a normal variant. Among true aberrations (5/81 or 6.2%), we found two de novo subtelomeric deletions and three unbalanced subtelomeric rearrangements (one de novo). All five were confirmed by MLPA. CGH was used to investigate the whole genome of patients in whom a subtelomeric anomaly was found, and confirmed some, but not all subtelomeric rearrangements. Our study estimated the frequency of subtelomeric abnormalities in patients with mental retardation and/or developmental disabilities and determined the feasibility of using these three methods in clinical testing. We concluded that T-FISH and MLPA are both very useful and interchangeable methods for detecting unbalanced chromosome rearrangements, while the resolution of CGH is too low for subtelomeric screening compared to TFISH and MLPA.
Descriptors		MENTAL RETARDATION IN SITU HYBRIDIZATION, FLUORESCENCE