Detection of chromosomal imbalances using combined MLPA kits in patients with syndromic intellectual disability

Revista Romana De Medicina De Laborator

et al. 2018

Small supernumerary marker chromosome (sSMC) is a rare chromosomal abnormality and is detected in about 0.3% in cases with multiple congenital anomalies (MCA) and/or developmental delay. Different techniques for investigation of cases with MCA and/or developmental delay are available ranging from karyotyping to molecular cytogenetic technique and ultimately multiplex ligation dependent probe amplification (MLPA). Here we present a patient with multiple congenital anomalies for which classical cytogenetic technique was used as a first step in diagnosis and the results being confirmed by MLPA. The karyotype disclosed a sSMC considered to be a fragment of chromosome 22. The MLPA analysis using SALSA MLPA probemix P064-C2 Microdeletion Syndromes-1B confirmed the karyotype results, and according to the manufacturer’s recommendation we performed another confirmation analysis with MLPA probemix P311-B1 Congenital Heart Disease and MLPA probemix P250-B2 DiGeorge. We also suspected an Emanuel syndrome and performed another MLPA analysis with SALSA MLPA probemix P036-E3 Subtelomeres Mix 1 and probemix P070-B3 Subtelomeres Mix 2B for investigation of subtelomeric region that revealed a duplication of 11q25 region and the confirmation was performed using SALSA MLPA probemix P286-B2 Human Telomere-11. In conclusion, we consider that MLPA is a valuable method for identification of sSMC in children with developmental delay and congenital anomalies. Genetic diagnosis using different molecular techniques, such as MLPA, for increasing accuracy in identification of chromosomal structural aberrations has an important role in clinical diagnosis and in genetic counselling and our case explain the importance of using a specific laboratory technique for each stage of diagnosis.

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Multiplex ligation dependent probe amplification - A useful, fast and cost-effective method for identification of small supernumerary marker chromosome in children with developmental delay and congenital heart defect

Crauciuc

Revista Romana De Medicina De Laborator

et al. 2018

“…MLPA, a multiplex technique, allows identification of deletions and duplications of the several DNA sequences in the same reaction (www. mlpa.com) or chromosomal changes of interest that remain undetected using other molecular techniques, like DNA sequencing (21,22). Also, the MLPA method may be considered as a good alternative to array-based techniques for many genetic disorders for the routine application (www.mlpa.com).…”

Section: Discussionmentioning

confidence: 99%

The utility of molecular genetic techniques in craniosynostosis cases associated with intellectual disability

Revista Romana De Medicina De Laborator

Bănescu

2018

Molecular genetic testing in craniosynostosis leads to the detection of the mutations in the genes encoding fibroblast growth factor receptors (FGFR), providing information about the etiology of the genetic disorder. Muenke syndrome is produced by p.Pro250Arg mutation in FGFR3 gene with evidence of variable expressivity, representing 8% of the syndromic craniosynostoses. Here, we present the identification of a p.Pro250Arg pathogenic mutation (c.749C>G) in the FGFR3 gene using Multiplex Ligation-dependent Probes Amplification (MLPA) analysis in conjunction with Sanger sequencing in a patient with craniosynostosis and mild intellectual disability. The MLPA analysis detected a reduced signal of the probe, at the site of the c.749C>G mutation, defined by the presence of one allele of C749>G mutation in the FGFR3 gene, exon 7. Sanger sequencing was performed for confirmation and identified heterozygous p.Pro250Arg pathogenic variant (c.749C>G) in exon 7 of the FGFR3. In conclusion, we assessed the validity and clinical utility of the combined molecular genetic techniques, MLPA analysis, and Sanger sequencing, for craniosynostosis and intellectual disability, improving not only the diagnostic testing but also the genetic counseling and management of the disorder.

“…[ 1 ] ID represents a reduction in cognitive abilities that appear before the age of 18 years and influences approximately 1% to 3% of the general population. [ 4 , 5 ]…”

Section: Introductionmentioning

confidence: 99%

Exon 21 deletion in the OPHN1 gene in a family with syndromic X-linked intellectual disability

Cosma²,

et al. 2020

Medicine

Introduction: The oligophrenin-1 ( OPHN1 ) gene, localized on the X chromosome, is a Rho-GTPase activating protein that is related to syndromic X-linked intellectual disability (XLID). XLID, characterized by brain anomalies, namely cerebellar hypoplasia, specific facial features, and intellectual disability, is produced by different mutations in the OPHN1 gene. Patient concerns: In this report, we present the clinical and molecular findings of a family affected by a mild XLID due to a deletion in the OPHN1 gene, exon 21, Xq12 region using Multiplex Ligation-dependent Probe Amplification (MLPA) analysis. The clinical features present in the family are a mild developmental delay, behavioral disturbances, facial dysmorphism, pes planus, nystagmus, strabismus, epilepsy, and occipital arachnoid cyst. Interventions: The MLPA analysis was performed for investigation of the copy number variations within the X chromosome for the family. Diagnosis and outcome: The MLPA analysis detected a deletion in the OPHN1 gene, exon 21 for the proband, and a heterozygous deletion for the probands mother. The deletion of the Xq12 region of maternal origin, including the exon 21 of the OPHN1 gene, confirmed for the probands nephew. Lessons: Our findings emphasize the utility of the MLPA analysis to identify deletions in the OPHN1 gene responsible for syndromic XLID. Therefore, we suggest that MLPA analysis should be performed as an alternative diagnostic test for all patients with a mild intellectual disability associated or not with behavioral disturbances, facial dysmorphism, and brain anomalies.