Moebius sequence and autism spectrum disorders--less frequently associated than formerly thought.

Moebius sequence is a rare congenital disorder usually defined as a combination of facial weakness with impairment of ocular abduction. It is questionable, whether there is a strong association of the sequence with autism spectrum disorders (ASDs) as suggested in some earlier case reports and studies. Twenty-two participants with Möbius sequence aged 6-16 years followed a request of the German Moebius foundation to participate in a nationwide study. All patients had a physical examination and intelligence testing. Primary caregivers were asked to complete two screening measures of ASD (Behaviour and Communication Questionnaire, VSK; Marburger Asperger's Syndrome Rating Scale, MBAS). For those who reached the cut-off for ASD and/or showed behavioural aspects indicative of ASDs during IQ testing and/or physical examination, well standardized diagnostic instruments (Autism Diagnostic Interview-Revised, Autism Diagnostic Observation Schedule, and Kinder-DIPS) were administered. Minimal diagnostic criteria for Möbius sequence were congenital facial weakness (uni- or bilateral) and impairment of ocular abduction (uni- or bilateral). Three boys (one of them mentally retarded) out of 22 participants (12 males and 10 females) were found suspicious of ASD by screening, but none of them fulfilled diagnostic criteria of ASD on a clinical consensus conference. Therefore, ASDs seem to be not as frequent as reported in previous studies on patients with Möbius sequence.