Bengaluru doctors detect new gene variant affecting brain growth
BENGALURU: A team of doctors in Bengaluru has identified a previously unknown KDM6B gene variant in a 10-year-old boy struggling with autism and developmental delays. The child, who also had Attention-Deficit/Hyperactivity Disorder (ADHD) traits, behavioural difficulties, toe-walking and speech delay, had been receiving therapies for years with little improvement, prompting his parents to seek further evaluation.
The boy underwent Whole Exome Sequencing– a genetic test that examines all key parts of a person’s DNA to detect changes that may cause the disease.
The test revealed a new mutation linked to Stolerman neurodevelopmental syndrome, a rare condition caused by defects in the KDM6B gene. This mutation had not been reported in any previous cases, adding to the known genetic causes of autism-related disorders.
Routine tests such as MRI and metabolic screening did not explain the child’s difficulties. An electroencephalogram (EEG) procedure revealed an unusual brain activity but no seizures, which led doctors to probe deeper using genetic testing. The analysis found a novel nonsense variant (c.4389G>A; p.Trp1463Ter) that is predicted to affect the KDM6B protein, important for normal brain growth.
Dr Vykunta Raju KN, a pediatric neurologist at Bangalore Child Neurology and Rehabilitation Centre, said the case highlights the importance of genetics in complex developmental conditions.
“The child had multiple behavioural and developmental issues with no clear cause from routine tests. Genetic sequencing helped identify the underlying reason... A confirmed diagnosis helps us plan therapies better and allows parents to understand what to expect as the child grows,” he said.
Dr Syeda Zubeda, a medical geneticist and senior genetic counsellor at Strand Life Sciences, said genetic testing can uncover hidden causes in children with overlapping conditions. “Many children have developmental delays, behavioural issues, and autistic traits at the same time.
Genetic testing helps us identify the exact condition,” she said. She also stressed the role of counselling. “Families need help in understanding what the mutation means, the prognosis and the risk for future children. Counselling is essential,” she said.
The doctors noted that discovering this previously unreported KDM6B variant contributes to the growing understanding of genetic mutations linked to neurodevelopmental disorders.
They also stressed the importance of early evaluation and genetic testing for children with severe or unexplained developmental delays, as it can guide treatment, and help prevent recurrence in families.