Telomere Analysis

 

TELOMERE ANALYSIS / UNBALANCED TRANSLOCATIONS(P036)

This product is intended to to detect deletion(s) and/or duplication(s) in subtelomeric regions as a potential cause of developmental delay, dysmorphic features, other congenital abnormalities and/or pregnancy loss. It can be used on human DNA derived from peripheral blood, buccal swap, and uncultured amniocytes or chorionic villi. Detected abnormalities should always be confirmed by a designated MLPA follow-up probemix or other technique.

 

Clinical background: Aberrant copy numbers of subtelomeric regions, e.g. due to an unbalanced translocation, are a frequent cause of developmental delay and congenital abnormalities. MLPA probe mix P036 Subtelomeres Mix 1 is intended to identify individuals with a copy number change in one or more subtelomeric regions. Detection rates depend strongly on the patient cohort tested: Ahn et al. (2007) found a detection rate of 5.9% when testing 455 patients; Stegmann et al. (2008) obtained a detection rate of 3.9% when testing a patient cohort in which normal G-banding analysis did not detect any abnormalities. Note that MLPA cannot identify balanced rearrangements and has a lower detection rate than microarray analysis.

 

Probemix Content: P036-E2 Subtelomeres Mix 1 contains 47 MLPA probes with amplification products between 118 and 483 nts: 2 probes for each chromosome and 1 probe for the unique part of the Y chromosome. 41 probes are located in subtelomeric regions. No probes are present for the subtelomeric regions of the 5 acrocentric chromosomes (13, 14, 15, 21, 22). For these, an extra probe is included detecting the q arm (ex. “13p”), close to the centromere. The subtelomeric probes for chromosome X and Y are identical as they detect sequences in the pseudoautosomal regions (PAR1 and PAR2). More information is present in Table 1 of the product description.