Variability in Cognitive Behavioral Phenotypes in Klinefelter Syndrome (KS)and Other Sex Chromosomal Aneuploidies (SCAs)

Sex Chromosomal Aneuploidies (SCAs) are the most frequently occurring chromosomal abnormalities with an incidence of 1 in 450 births. Males with SCAs are known to have variability in their developmental profile. Aim of this paper is to illustrate clinical variability in the different SCAs. The sample was composed by 53 subjects (mean age=21.16 years, range: 13-54) with karyotype 47, XXY (73%), 49, XXXXY (7%), 48, XXYY (9%), mosaicism 47, XXY/48, XXXY (2%), 47, XYY (5%), 48, XXXY (2%), 49, XXXYY (2%). Only 5 subjects have been diagnosed prenatally (4 KS and 1 XXYY). Primary caregivers completed a comprehensive questionnaire detailing birth, medical, developmental and psychological history. Cognitive and behavioral assessment was performed with clinical interviews with DSM IV criteria and psychometric questionnaires (WISC-R, WAIS-R, CPM, Token Test, VABS, SCL90, and SCQ). Twenty-one sex and age matched subjects karyotypically normal were also evaluated from the behavioural point of view. Mean IQ in typical KS was 87.45 ± 2 ds (sd=20.12) range 45-123, VIQ 91.74 (sd=19.55) range 50-130 and PIQ 86.87 (sd=20.87) range 50-126. Mean IQ in other SCAs was 68.71 (sd=20.81) range 45-106, VIQ 69.36 (sd=21.97) range 47-113 and PIQ 74.72 (sd=21.70) range 45-112. In CPM KS subjects scored 27.75 (range 13-36) and 31.50 in the Token Test (range 21-35) while in CPM the other SCAs subjects scored 22.27 (range 10-35) and 22.50 (range 9-31) in the Token Test (p<0.05). VABS scores documented more marked impairment on adaptive behavior in atypical SCAs subjects. SCL90 documented an elevation of paranoid scale in the 70% of KS subjects and 50% of other SCAs. Autistic traits were present in 67% of the other SCAs subjects and in the 18% of KS at the SCQ. A precise identification of the cognitive and behavioral phenotype in different SCAs may enhance the clinical treatment, anticipatory guidance, and care throughout the lifespan.