Author/Editor		Erjavec-Škerget, Alenka
Title		Presejalni testi za iskanje kromosomskih sprememb pri idiopatski duševni manjrazvitosti
Type		monografija
Place		Ljubljana
Publisher		Medicinska fakulteta
Publication year		2006
Volume		str. 105
Language		slo
Abstract		The subtelomeric regions are interesting from a genomic perspective, as they are gene rich and often involved in chromosomal rearrangements. Most telomeres stain light with G-banding, and small rearrangements are therefore difficult to detect. Due to the development of molecular cytogenetics techniques, it is possible to identify cryptic rearrangements involving the ends of chromosomes. Screening method generally used for detection of subtelomeric rearrangements is multiprobe telomere fluorescent in situ hybridization (T-FISH). In the last few years the new method multiplex ligationdependent probe amplification (MLPA) became very reliable. With T-FISH we screened 100 patients (children and young adults, 0-19 years old) with idiopathic mental retardation (IMR) and / or dysmorphology and a normal kariotype. We recognized subtelomeric abnormalities in 10 patients (10 %). Four among them had a deletion of subtelomeric 2q, which was apparently normal variant. Among true aberrations (6 %) we found two subtelomeric deletion (one de novo) and four unbalanced subtelomeric rearrangements (one de novo). MLPA reviled all six of confirnved anomalies. With comparative genomic hybridization (CGH) we investigate the whole genome of patients where the subtelomeric anomaly was found. We confinned subtelomeric rearrangements bigger than 8Mb. Our study was used for further estimation of frequency of subtelomeric abnormalities in the patients with mental retardation and/or development disabilities and to determine the feasibility of using these three methods (T-FISH, MLPA and CGH) in clinical testing. All methods are efficient for routine cytogenetics diagnostic by IMR, congenital anomalies and by resolving complex karyotypes. (Abstract truncated at 2000 characters)
Descriptors		MENTAL RETARDATION CHROMOSOME ABERRATIONS KARYOTYPING IN SITU HYBRIDIZATION, FLUORESCENCE NUCLEIC ACID HYBRIDIZATION