Evaluation of Chromosome Microarray Analysis in a Large Cohort of Females with Autism Spectrum Disorders: A Single Center Italian Study.
Chromosomal microarray gives a genetic why for one in five girls with unexplained autism and flags a milder repetitive-behavior profile.
01Research in Context
What this study did
Doctors in Italy ran chromosome microarray tests on 90 girls with autism. All of the girls had no known genetic cause for their autism.
The team wanted to see how many carried copy-number variants that could explain their symptoms. They also checked if those variants linked to milder or tougher behavior profiles.
What they found
Twenty-two percent of the girls had a likely causative CNV. That is about one in every five tested.
Girls with these CNVs showed fewer restrictive and repetitive behaviors than girls without them. The difference was clear enough for the lab to notice.
How this fits with other research
Older karyotype papers like Gaily et al. (1998) and Konstantareas et al. (1999) found chromosomal problems in only 3% of autistic kids. The new CMA tool lifts the pick-up rate to 22%, so the older low-yield studies are now superseded.
The same Italian center later published Palka Bayard de Volo et al. (2021), a larger mixed-sex cohort that again reported a 22% CNV yield. The numbers line up so well that the 2021 paper seems to directly replicate the 2020 female-only results.
Al-Mamari et al. (2015) tested a consanguineous group and saw a 27% yield. Despite different ancestry and sex mix, the yield stays in the same ball-park, showing the test is robust across populations.
Why it matters
If you work with girls who have idiopathic autism, consider a referral for chromosomal microarray. About one-fifth will get a genetic answer, and those kids may present with slightly fewer repetitive behaviors. Sharing this finding with families can guide counseling and tailor your behavior plans.
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02At a glance
03Original abstract
Autism spectrum disorders (ASD) encompass a heterogeneous group of neurodevelopmental disorders resulting from the complex interaction between genetic and environmental factors. Thanks to the chromosome microarray analysis (CMA) in clinical practice, the accurate identification and characterization of submicroscopic deletions/duplications (copy number variants, CNVs) associated with ASD was made possible. However, the widely acknowledged excess of males on the autism spectrum reflects on a paucity of CMA studies specifically focused on females with ASD (f-ASD). In this framework, we aim to evaluate the frequency of causative CNVs in a single-center cohort of idiopathic f-ASD. Among the 90 f-ASD analyzed, we found 20 patients with one or two potentially pathogenic CNVs, including those previously associated with ASD (located at 16<i>p</i>13.2 16<i>p</i>11.2, 15<i>q</i>11.2, and 22<i>q</i>11.21 regions). An exploratory genotype/phenotype analysis revealed that the f-ASD with causative CNVs had statistically significantly lower restrictive and repetitive behaviors than those without CNVs or with non-causative CNVs. Future work should focus on further understanding of f-ASD genetic underpinnings, taking advantage of next-generation sequencing technologies, with the ultimate goal of contributing to precision medicine in ASD.
, 2020 · doi:10.3390/jpm10040160