Clinical Characteristics

Main clinical features compromise variable developmental delay (speech and language are generally more affected than motor development)/intellectual disability, autism spectrum disorders (ASD) and other behavioral issues such as hyperactivity, microcephaly, (tendency) to obesity, feeding and/or gastro-intestinal problems, and vision problems. In a smaller subset seizures, sleeping problems and congenital heart and kidney problems are reported. With respect to the behavioral phenotype it is remarkable that despite a diagnosis of autism, many patients have a seemingly contrary overly friendly and/or social demeanor. In many patients mild dysmorphic facial features, including brachycephaly and a broad forehead, can be recognized, however the facial phenotype is not very specific or recognizable.