To evaluate the feasibility of screening large cohorts of patients with developmental delay or intellectual disability (DD/ID) with multiplex ligation-dependent probe amplification (MLPA).
The peripheral blood samples were collected and DNA extracted from 276 patients with DD/ID from June 2012 to December 2013. MLPA was employed, including two distinct kits SALSA P036 and P070 for sub-telomere screening and SALSA P245 for 22 common microdeletion and microduplication syndromes.
MLPA analysis revealed 58 (21%) cases of chromosome aberrations. Among 32 cases of subtelomeric rearrangements on one chromosome, there were deletion (n = 25) and duplication (n = 7); subtelomeric deletions on p and q arms of one chromosome (n = 2); subtelomeric rearrangements on 2 chromosomes, one deletion and other duplication (n = 9); subtelomeric rearrangements on 3 chromosomes, 2 duplications and other deletion (n = 1). There were 1 case of subtelomeric rearrangements on chromosome X. A total of 11 syndromes were detected among 22 common microdeletion and microduplication syndromes and 6 located at subtelomeric regions.
MLPA is an effective cytogenetic diagnostic tool for detecting chromosomal abnormalities, such as DD/ID.