Special clinical entity with 15q26 deletion: a novel case report

Abstract

In the past, there were no easily distinct and recognizable features as a guide for precise clinical and genetic diagnosis of cases with chromosome microdeletions involving 15q26 including CHD2. The present study analysed the clinical data and collected venous blood samples from a pediatric patient and his healthy family members for DNA testing. The whole-exome sequencing was performed by the next-generation sequencing (NGS). Chromosomal copy-number variations were tested based on NGS. We present a review of all cases with chromosome microdeletions affecting CHD2. A novel de novo 5.82-Mb deletion at 15q25.3-15q26.1 including CHD2 was identified in our patient who is an 11.6-year-old boy. We first found surprising efficacy of lamotrigine in controlling intractable drop seizures in the individual. These cases have development delay, behavioural problems, epilepsy, variable multiple anomalies, etc. Phenotypes of individuals with deletions involving 15q26 including CHD2 are highly variable with regard to facial features and multiple developmental anomalies. We first found the special clinical entity of development delay, behavioural problems, epilepsy, variable skeletal and muscular anomalies, abnormalities of variable multiple systems and characteristic craniofacial phenotypes in patients with chromosome microdeletions involving CHD2. The larger deletions involving 15q26 including CHD2 tend to cause the classical phenotype. A distinctive craniofacial appearance of the classical phenotype is midface hypoplasia and perifacial protrusion.