[Multiplex Ligation - dependent Probe Amplification (MLPA) as a screening test in children with developmental defects and intellectual disability of unknown etiology]

Abstract

Developmental delay and intellectual disability are significant medical and social problems which concern 1-3% of population. The etiology remains unknown in over half of the cases.

The aim: To evaluate the efficiency of MLPA (Multiplex Ligation-dependent Probe Amplification) as a screening test in diagnosis of patients with developmental delay and/or intellectual disability.

Material and methods: 313 MLPA tests were performed in 256 patients with developmental delay and/ or intellectual disability with unknown etiology. MLPA test was made after exclusion of genetic disorders possible to diagnose by dysmorphological examination or using specifi c genetic tests. Positive results were confirmed by FISH analysis with appropriate probes.

Results: Chromosomal microaberrations were identifi ed in 15 patients (4,8%): deletions of 1p36 in 4 cases, in one case deletion of 22q11.21, 22q13.33, SNRPN1, 4ptel, 6qtel, 7q11.23, 16ptel, 18qtel as well as one ca se of deletion 3ptel/duplication 15qtel; deletion 18qtel/duplication Xqtel, and also duplication 7q11.23. Detail clinical analysis was performed in patients with diagnosed microaberrations in MLPA test.

Conclusions: The molecular MLPA test, screening for chromosomal microaberration syndromes, should be performed in each patient with developmental delay and/or intellectual disability of unknown etiology and normal cytogenetic analysis, even if congenital defects and positive familial history do not exist.