Brief report: systematic review of Rett syndrome in males.

Brian and his team hunted every published case of Rett syndrome in boys. They found 57 reports written between 1966 and 2013.

For each boy they noted genes, symptoms, and how doctors made the diagnosis. Then they tallied the numbers.

More than half of the boys (a large share) had a glitch in the MECP2 gene. Two-thirds (a large share) also carried extra or missing pieces of other chromosomes.

Bottom line: Rett in males is rare, but when it shows up, MECP2 is still the usual suspect.

Galuska et al. (2006) showed that people with MECP2 mutations can sometimes keep talking and have milder bodies. Brian’s review includes those same mild cases, so the two papers fit like puzzle pieces.

Casey et al. (2009) reviewed a different gene disorder (TSC) and also linked a single gene to thinking problems. Both reviews say: find the gene, understand the behavior.

Oliveira et al. (2003) reported a boy with autism and a chromosome 3q problem, not MECP2. That case sits outside the Rett world, showing why you must test the right gene.

If you assess a boy who stops talking, wrings his hands, and loses motor skills, don’t rule out Rett. Order MECP2 testing first; it will catch roughly half of male cases. When that test is negative, cast a wider net—array CGH can spot the extra chromosomal bits Brian found. Early gene answers give families a name and guide your behavior plan.