The 16p11.2 deletion or duplication mutation is found on chromosome 16, and prevalent in approximately 1% of people with ASD. The findings of a longitudinal study about 16p11.2 deletion and duplication suggest distinct developmental trajectories. Fifty-six children with these mutations (33 with a 16p11.2 deletion and 23 with a duplication) were followed for several years in order to observe developmental changes. Spectrum News posted a great article about the study, performed by the Bernier Lab and colleagues. Below are excerpts pulled from the article, and the full text can be found here: https://spectrumnews.org/news/chromosome-16-mutations-augur-distinct-developmental-paths/
- Deletions typically lead to an enlarged head and obesity, whereas duplications result in a smaller head and low body weight. Both mutations are associated with language problems, intellectual disability and autism.
- The children with a deletion showed declines in motor and social skills, whereas those with a duplication remained relatively stable in these areas. Both groups of children showed an increase in verbal IQ — which is expected with age — but their behaviors and nonverbal IQ remained relatively stable.
- The researchers did not detect any patterns that distinguish the subset of deletion carriers with autism from the rest of the children with the deletion.
- Among children with a duplication, those who have autism have weaker communication and social skills and lower verbal and nonverbal IQs at age 2 than do those without autism. They also show losses in motor skills and greater gains in verbal IQ with age than those without autism.
Bernier R. et al. Am. J. Med. Genet. B Neuropsychiatr. Genet. 174, 367-380 (2017) PubMed