Two children with muscular dystrophies ascertained due to referral for diagnosis of autism.

Two preschool boys were sent to an autism clinic. Both had language delays and poor eye contact.

The team ran blood work. Creatine kinase (CK) came back sky-high. Muscle biopsy proved muscular dystrophy.

Autism-like behaviors can be the first sign of a muscle disease.

A simple CK blood test caught a life-shortening illness that looks like ASD.

Almatrafi et al. (2023) later found creatine-transporter deficiency in brothers with ASD. Both papers say: when you see autism plus low tone or motor delay, draw blood for metabolic clues.

Wang et al. (2010) seems to disagree. They screened urine creatine in the kids with ASD and found nothing extra. The trick is CK, not urine. CK flags muscle breakdown; urine creatine does not.

Lloyd et al. (2013) show motor gaps widen fast in toddlers with ASD. Pair that with Lonnie’s warning and you have reason to add a quick neuromotor exam to every autism intake.

You can miss muscular dystrophy if you only watch behavior. Add two minutes: ask about stairs, jumping, and calf size. If any red flag, order CK. Early diagnosis gives families access to steroids and cardiac care that add years of walking.