RESUMO
BACKGROUND: Retinoblastoma (RB) is the most common primary intraocular malignant tumor in children. RB is mostly caused by biallelic mutations in RB1 and occurs in hereditary and non-hereditary forms according to the "two-hit" theory. RB1 mutations comprise point mutations, indels, large deletions, and duplications. Genetic testing is essential for the comprehensive treatment and management of patients with RB. AIM: The aim was to evaluate RB1 copy number variations (CNVs) using MLPA versus FISH assays in group of Egyptian patients with RB. RESULTS: 16.67% showed an RB1 deletion, abnormal methylation status, or both. CONCLUSION: Our results suggested MLPA is a fast, reliable, and powerful method and should be used as a first-line screening tool for detecting RB1 CNVs in patients with RB. Moreover, MLPA is advantageous as it evaluates the methylation status/inactivation of RB1, not possible by FISH.
Assuntos
Neoplasias da Retina , Retinoblastoma , Humanos , Retinoblastoma/diagnóstico , Retinoblastoma/genética , Retinoblastoma/patologia , Variações do Número de Cópias de DNA , Reação em Cadeia da Polimerase Multiplex , Hibridização in Situ Fluorescente , Egito/epidemiologia , Neoplasias da Retina/diagnóstico , Neoplasias da Retina/genética , Neoplasias da Retina/patologia , Ubiquitina-Proteína Ligases/genética , Proteínas de Ligação a Retinoblastoma/genéticaRESUMO
BACKGROUND: Insulin-like growth factor-1 (IGF-1) is required for normal intrauterine and postnatal growth, and this action is mediated through IGF1 receptor (IGF1R). IGF1R copy number variants (CNVs) can cause pre- and postnatal growth restriction, affecting an individual's height. In this study, we used multiplex ligation-dependent probe amplification (MLPA) to detect CNVs in IGF1R, IGFALS, and IGFBP3 genes in the diagnostic workup of short stature for 40 Egyptian children with short stature. RESULTS: We detected a heterozygous deletion of IGF1R (exons 4 through 21) in 1 out of the 40 studied children (2.5%). Meanwhile, we did not detect any CNVs in either IGFALS or IGFBP3. CONCLUSION: The diagnostic workup of short stature using MLPA for CNVs of IGF1R and other recognized height-related genes, such as SHOX and GH, in non-syndromic short stature children can be a fast and inexpensive diagnostic tool to recognize a subcategory of patients in which growth hormone treatment can be considered.
