[Genetic study of 20 patients with autism disorders].
BACKGROUND
Many observations indicate that genetic factors play an important role in the aetiology of autism. Up to now, however, no genetic markers have been convincingly identified which influence the predisposition to this disorder. Complex genetic analysis of autistic patients and their families may therefore lead to the identification of features which could help to direct further search for the predisposing genes.


RESULTS
We have analysed a sample of 20 patients with autism spectrum disorders. The patients have been subjected to clinical genetic examination, cytogenetic analysis and DNA analysis of the FMR1 gene. In the sample studied we have observed more boys (15/20), various degree of mental retardation (18/20), high frequency of complications during pregnancy (10/20) and delivery (10/20), increased incidence of psychiatric disorders, behavioural abnormalities and suicides among the relatives, and increased head circumference and unusually formed ears in the probands. Three patients had different chromosomal aberrations or variants (t(21;22), inv(9) and inv(10)). One patient harboured expansion of the trinucleotide repeat sequence in the FMR1 gene on the full mutation level which is characteristic for the fragile X syndrome, and one patient is suspected to suffer from the Rett syndrome.


CONCLUSIONS
Our observations confirm and extend the results reported in the literature. Most interesting are mainly the macrocephaly which may be associated with the recently described increased neonatal levels of neural growth factors in autistic individuals, ear malformations which may indicate aberrations in the HOXA1 gene pathway, the occurrence of chromosomal inversions recurrent in autism, and peculiarities in the pedigrees of the patients.
Havlovicová
M
M
Ustav biologie a lékarské genetiky, LF UK a FNM, Praha. marketa.havlovicova@lfmotol.cuni.cz
Propper
L
L
Novotná
D
D
Musová
Z
Z
Hrdlicka
M
M
Sedlácek
Z
Z
D000293:Adolescent; D000328:Adult; D001321:Autistic Disorder / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D020732:Cytogenetic Analysis; D005260:Female; D051860:Fragile X Messenger Ribonucleoprotein 1; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D008297:Male; D009419:Nerve Tissue Proteins / Q000235:genetics; D010375:Pedigree; D016601:RNA-Binding Proteins; D018911:Trinucleotide Repeats
D051860:Fragile X Messenger Ribonucleoprotein 1; D009419:Nerve Tissue Proteins; D016601:RNA-Binding Proteins; C497683:FMR1 protein, human