Klinefelter’s Syndrome in the Young Adult

Extant literature shows that Klinefelter syndrome (KS) is a chromosomal condition that affects the male physical, psychosocial and cognitive capacities due to the presence of one or more supernumerary X chromosomes among the affected individuals. With an occurrence rate of 1:500 to 1:1000 live male births, affected persons exhibit a multiplicity of signs and symptoms such as hypogonadism, fertility problems due to low testosterone, decreased body and pubic hair, tall stature, gynecomastia, language-based learning incapability, and disorders of the executive function (Turriff et al., 2011; Verri et al., 2010).

KS remains a common yet underdiagnosed genetic condition due to its high variability among individuals, overlapping of symptoms with those of other medical conditions, and complexities in clinical manifestation (Genetic Home Reference, 2013; Herlihy et al., 2011). The present paper aims to illuminate the cognitive and psychosocial aspects of a male with KS in the post-puberty stage.

Although cognitive characteristics vary among affected individuals, available literature demonstrates that a considerable number of young adults with KS exhibit learning disabilities and delayed speech and language development (Genetic Home Reference, 2013) caused by chromosomal abnormalities (van Rijn et al., 2012). A study by Verri et al (2010) shows that 70-80% of XXY males demonstrate language disabilities that are exhibited in terms of delay in onset of first words, acquisition of the main phases of language development and challenges in the articulation of sounds or syllables in lexical retrieval and processing of phonemes, resulting in limitations in reading, expression, writing and reasoning abilities in arithmetic (Verri et al., 2010).

Verri et al (2010) acknowledge that “individuals with KS have limitations in material processing speed and memory of auditory verbal material, which are associated with problems in decoding words” (p. 426). Cognitively, therefore, these challenges result in a lower speed, accuracy and verbal comprehension, particularly when the reading of material is done aloud. Adults may not exhibit these symptoms probably due to experience gained over a long time, but they too exhibit distinctive characteristics of cognitive deficiencies (Turriff et al., 2011).

Substantial reduction in verbal scale and IQ performance has been noted in young adults diagnosed with atypical aneuploidy (e.g., XXXY 48 and 49 XXXXY) compared with those exhibiting the XXY variant (Verri et al., 2010), demonstrating that cognitive limitations are correlated with an increasing number of supernumerary X chromosomes (van Rijn et al., 2012).

It has also been reported in the literature that young adults with KS are hyperactive, demonstrate difficulties in concentration and short-term memory, and also project a docile temperament and lower activity levels compared with unaffected peers within the general population (Herlihy et al., 2011; Verri et al., 2010).

Indeed, as reported by Verri et al (2010), “in a population of KS aged 16 and 61, younger subjects have lower performance in tasks that require executive functions, problem-solving skills and speed in processing the information, whereas adults show adequate performance” (p. 427). This finding is critical in demonstrating that the cognitive performance of young adults diagnosed with KS may actually improve as they progress through the lifespan due to experience. However, these individuals need to be exposed to speech, educational and cognitive interventions earlier in life to improve later outcomes (Herlihy et al., 2011).

In psychosocial aspects, extant literature demonstrates that lack of incomplete puberty, breast enlargement (gynecomastia), unusually small penis (micropenis), speech and languages deficiencies and other physical, developmental and cognitive challenges posed by KS may lead to poor socialization and lack of integration of the affected young adults within the peer group (Genetics Home Reference, 2013; Turriff et al., 2011). These challenges, according to Verri et al (2010), act as a source of anxiety and mood disorders, shyness, immaturity and incapacity to establish intimate relationships with significant others.

Indeed, according to Verri et al (2010), most young adults exhibiting KS symptoms “seem to be more sensitive, anxious and insecure, and show a higher incidence of anxious-depressive disorders than the general population and an increased propensity to use drugs” (p. 428). The literature is also unanimous on other psychosocial characteristics exhibited by young adults with KS, including atypical calmness, sensitivity to the immediate environment, lack of assertiveness, depression, closure, low self-esteem, passiveness and problems in socialization (Herlihy et al., 2011; Verri et al., 2010).

In most occasions, these aspects combine with unattended learning difficulties and limitations in normal developmental processes to result in secondary adaptation and behavioral challenges for the affected individuals. This scenario compromises the individual’s quality of life outcomes, including subjective well-being, interpersonal relationships, self-esteem, body image, mental health and general health, leading to high school dropout rates, antisocial behavior, sickness and deviance (Herlihy et al., 2011).

There are a number of opposing views concerning the presence and occurrence of KS. To date, some people think that KS results from the presence of one extra copy of the X chromosome in each cell; however, available literature has proved that some individuals with characteristics of KS may indeed have more than one extra X chromosome in each cell (e.g., 48, XXXY or 49, XXXXY), resulting in more severe signs and symptoms than classic KS (Verri et al., 2010).

Other people have argued that KS and its variants are inherited; however, research has proved that the chromosomal shifts normally occur during the development of reproductive cells in a parent and the extra X chromosome is essentially caused by an error in cell division (Genetics Home Reference, 2013). Lastly, although some studies have found KS subjects to have a general cognitive capacity around the normal range, the correct position is that the cognitive ability demonstrated by KS subjects is approximately 10 points lower compared to normal individuals within the general population (Verri et al., 2010).


Genetics Home Reference. (2013). Klinefelter syndrome. Web.

Herlihy, A.S., McLachlan, R.I., Gillam, L., Cock, M.L., Collins, V., & Halliday, J.L. (2011). The psychosocial impact of Klinefelter syndrome and factors influencing quality of life. Genetics in Medicine, 13(7), 632-642.

Turriff, A., Levy, H.P., & Biesecker, B. (2011). Prevalence and psychosocial correlates of depressive symptoms among adolescents and adults with Klinefelter syndrome. Genetics in Medicine, 13(11), 966-972.

Van Rijn, S., Bierman, M., Bruining, H., & Swaab, H. (2012). Vulnerability for autism traits in boys and men with an extra X chromosome (47, XXY): The mediating role of cognitive flexibility. Journal of Psychiatric Research, 46, 1300-1306.

Verri, A., Cremante, A., Clerici, F., Destefani, V., & Radicioni, A. (2010). Klinefelter’s syndrome and psychoneurologic function. Molecular Human Reproduction, 16(6), 425-433.