Article

Sex chromosome aneuploidies increase the risk of spoken or written language
disorders but individuals with specific language impairment (SLI) or dyslexia do
not routinely undergo cytogenetic analysis. We assess the frequency of sex
chromosome aneuploidies in individuals with language impairment or dyslexia.
METHOD: Genome-wide single nucleotide polymorphism genotyping was performed in
three sample sets: a clinical cohort of individuals with speech and language
deficits (87 probands: 61 males, 26 females; age range 4 to 23 years), a
replication cohort of individuals with SLI, from both clinical and
epidemiological samples (209 probands: 139 males, 70 females; age range 4 to 17
years), and a set of individuals with dyslexia (314 probands: 224 males, 90
females; age range 7 to 18 years). RESULTS: In the clinical language-impaired
cohort, three abnormal karyotypic results were identified in probands (proband
yield 3.4%). In the SLI replication cohort, six abnormalities were identified
providing a consistent proband yield (2.9%). In the sample of individuals with
dyslexia, two sex chromosome aneuploidies were found giving a lower proband yield
of 0.6%. In total, two XYY, four XXY (Klinefelter syndrome), three XXX, one XO
(Turner syndrome), and one unresolved karyotype were identified. INTERPRETATION:
The frequency of sex chromosome aneuploidies within each of the three cohorts was
increased over the expected population frequency (approximately 0.25%) suggesting
that genetic testing may prove worthwhile for individuals with language and
literacy problems and normal non-verbal IQ. Early detection of these aneuploidies
can provide information and direct the appropriate management for individuals.
CI - (c) 2013 The Authors. Developmental Medicine & Child Neurology published by John
Wiley & Sons Ltd on behalf of Mac Keith Press.

Langue : ANGLAIS