Elective (or selective) mutism is a rare psychiatric disorder. Diagnostic criteria in both ICD-101 and DSM-IV2 include: (a) consistent failure to speak in specific social situations in which there is an expectation for speaking (for example, at school) despite speaking in other situations (for example, at home); (b) the disturbance interferes with educational or occupational achievement or with social communication; (c) it is not better accounted for by a communication disorder or by a lack of knowledge of the spoken language required in the social situation; (d) it has a duration of at least 1 month.3

It typically starts at preschool age, is more common in girls, and is seen in all social strata with shyness, withdrawal, sensitivity or resistance, and internalising behaviour problems as the most common personality features.

We followed up a 7.5 year old girl who was the third child from non-consanguineous parents. She was born normally at 37 weeks of an uneventful pregnancy, with a birth weight of 3,5 kg, length 47 cm, and head circumference 34.5 cm. The American pediatric gross assessment record was 9 at 5 minutes. Family history was non-contributory. There was neither family history of psychiatric illness nor of language abnormalities.

Developmental milestones were normal; she acquired head control at the 3rd month of life, sat at 7 months, and walked at 13 months. On the other hand, she …