Association of a balanced chromosomal translocation (4; 12)(q21.3; q15), affective disorder and autism.

Doctors looked at twin boys who had autism, severe intellectual disability, and mood swings.

A lab test called a karyotype showed a new balanced swap between chromosome 4 and chromosome 12.

The report simply describes the swap; no therapy was tried or tested.

The twins carry t(4;12)(q21.3;q15), a rare balanced translocation never before seen with autism.

Because the break points may disturb genes, the finding adds a new spot for geneticists to watch.

Castermans et al. (2004) and Poulson (1998) say balanced swaps are useful signposts for finding autism genes.

Osei-Owusu et al. (2020) and Fullana et al. (2007) each found a different rare swap in one autistic child.

All together, the papers agree that odd chromosomal moves can travel with autism; they simply point to different addresses on the chromosomes.

If you serve a client who has autism plus mood issues and unexplained delays, ask the medical team if a karyotype was done. A rare swap like t(4;12) will not change your ABA plan, but it can explain etiology to families and alert physicians to watch for other syndromic traits.