Analysis index

5 ml EDTA-blood and consent declaration. We also recommend human genetic consultation where applicable.

Intellectual disabilities, facial dysmorphia, macroorchidism, autism

Fragile X-syndrome is the second most common congenital cause for mental disability (prevalence 1:2000 in male children) after Down’s syndrome. The clinical presentation reaches from mental retardation, facial dysmorphia with elongated face, protruding forehead, long nose and protruding chin, macroorchidism, developmental delays (especially speech delays) and signs of autism. Individual symptoms may vary in degree. Etiologically there is a CGG-triplet expansion in the FMR1-gene in 99 % (normal persons: 6 – 54 triplets, pre-mutation carriers (without symptoms): 55 – 200 triplets, sufferers: > 200 triplets), the remaining 1 % are caused by mutation or deletions. The amount of triplet repetitions increases with each reduction division, so that the illness gets more severe with each generation (anticipation). Pre-mutation carriers may develop a so-called fragile X tremor-ataxia- syndrome with movement disorders and cognitive deficits later in life. Contrary to other X-chromosomal congenital diseases, in the fragile X-syndrome women with full mutation may show clinical abnormalities, usually a variable intelligence retardation. Thus, differential diagnostically the fragile X-syndrome should always be considered in patients with intellectual deficits and/or autism.

MVZ Dr. Eberhard & Partner Dortmund