Chromosomal abnormalities in a series of children with autistic disorder.

Doctors looked at the chromosomes of 127 children with autism. Only eight kids had usable karyotype pictures. The team wanted to see if any pieces of DNA were missing or extra. They also checked if those DNA changes linked to IQ or autism severity.

Eight children showed different chromosome problems. These kids scored lower on cognitive tests. Their autism ratings, however, looked the same as the rest. In short, DNA changes mattered for smarts, not for core autism traits.

Gaily et al. (1998) ran a near-copy study one year earlier. They tested 92 kids and found a 3 % anomaly rate. Konstantareas et al. (1999) saw roughly 6 %. The numbers differ because more children were checked and lab methods improved.

Al-Mamari et al. (2015) and Duerden et al. (2012) used a sharper tool called chromosomal microarray. They found problems in 24–27 % of autistic patients. Their higher yield does not clash with the 1999 data; it simply shows better technology finds smaller DNA bits.

Hutchins et al. (2020) extended the idea to girls only. CMA again spotted causal variants in 22 % of females. Together these newer papers supersede the old karyotype counts and push microarray to the front of genetic work-ups.

You may meet children with both autism and low IQ. A microarray test can reveal a cause in about one of every four cases. A clear genetic answer helps families plan and can guide medical care. When you write assessment plans, list chromosomal microarray before older karyotype requests.