Other Variations

/Other Variations

Klinefelter Syndrome and Other Sex Chromosomal Aneuploidies

Article Title: Klinefelter syndrome and other sex chromosomal aneuploidies

Author: Jeannie Visootsak and John M. Graham Jr.

Date of Publication: October 24, 2006

The term Klinefelter syndrome (KS) describes a group of chromosomal disorder in which there is at least one extra X chromosome to a normal male karyotype, 46,XY. XXY aneuploidy is the most common disorder of sex chromosomes in humans, with prevalence of one in 500 males. Other sex chromosomal aneuploidies have also been described, although they are much less frequent, with 48,XXYY and 48,XXXY being present in 1 per 17,000 to 1 per 50,000 male births. The incidence of 49,XXXXY is 1 per 85,000 to 100,000 male births. In addition, 46,XX males also exist and it is caused by translocation of Y material including sex determining region (SRY) to the X chromosome during paternal meiosis. Formal cytogenetic analysis is necessary to make a definite diagnosis, and more obvious differences in physical features tend to be associated with increasing numbers of sex chromosomes. If the diagnosis is not made prenatally, 47,XXY males may present with a variety of subtle clinical signs that are age-related. In infancy, males with 47,XXY may have chromosomal evaluations done for hypospadias, small phallus or cryptorchidism, developmental delay. The school-aged child may present with language delay, learning disabilities, or behavioral problems. The older child or adolescent may be discovered during an endocrine evaluation for delayed or incomplete pubertal development with eunuchoid body habitus, gynecomastia, and small testes. Adults are often evaluated for infertility or breast malignancy. Androgen replacement therapy should begin at puberty, around age 12 years, in increasing dosage sufficient to maintain age appropriate serum concentrations of testosterone, estradiol, follicle stimulating hormone (FSH), and luteinizing hormone (LH). The effects on physical and cognitive development increase with the number of extra Xs, and each extra X is associated with an intelligence quotient (IQ) decrease of approximately 15–16 points, with language most affected, particularly expressive language skills.

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2018-09-06T12:19:54+00:00Categories: 47,XXY (Klinefelter), 48,XXYY, Other Variations|

Clinical research: Extra X impairs awareness of others’ minds

Article Title: Clinical research: Extra X impairs awareness of others’ minds

Author: Kate Yandell

Date of Publication: June 13, 2014

“Girls and boys born with an extra X chromosome both tend to have difficulties understanding the minds of others, but for different reasons than children with autism do, according to a study published 22 March in Genes, Brain and Behavior” (Sophie van Rijn et al).

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Effects of short-course androgen therapy on the neurodevelopmental profile of infants and children with 49,XXXXY syndrome

Article Title: Effects of short‐course androgen therapy on the neurodevelopmental profile of infants and children with 49,XXXXY syndrome

Authors: Carole A. Samango‐Sprouse, Andrea L Gropman, Teresa Sadeghin, Madison Kingery, Margaret Lutz‐Armstrong, Alan D. Rogol

Date of Publication: March 1, 2011

“The aim of this investigation was to ascertain whether an early course of androgen treatment (three injections testosterone enanthate, 25 mg) could have a positive impact on any domains of neurodevelopmental function in boys with 49,XXXXY.

Our findings revealed improved function in several areas of development which had been severely delayed in boys with 49,XXXXY. Continued research is underway to expand our understanding of the relationship of androgen, brain function and behavioural outcome in boys with 49,XXXXY.”

2018-08-16T12:45:13+00:00Categories: Other Variations|Tags: |

48,XXYY, 48,XXXY and 49,XXXXY Syndromes: Not Just Variants of Klinefelter Syndrome

Article Title: 48,XXYY, 48,XXXY and 49,XXXXY syndromes: not just variants of Klinefelter syndrome

Authors: Tartaglia, Ayari, Howell, D’Epagnier, Zeitler

Date of Publication: April 9, 2011

Sex chromosome tetrasomy and pentasomy conditions occur in 1:18,000-1:100,000 male births. While often compared with 47,XXY/Klinefelter syndrome because of shared features including tall stature and hypergonadotropic hypogonadism, 48,XXYY, 48,XXXY and 49,XXXXY syndromes are associated with additional physical findings, congenital malformations, medical problems and psychological features.”

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2018-08-17T16:45:49+00:00Categories: 48,XXYY, Other Variations|Tags: |

What is Intersex?

Article Title: What is Intersex?

Authors: Organisation Intersex International Australia Limited

Date of Publication: 2010

“INTERSEX is congenital difference in anatomical sex. That is, physical differences in reproductive parts like the testicles, penis, vulva, clitoris, ovaries and so on. Intersex is also physical differences in secondary sexual characteristics such as muscle mass, hair distribution, breast development and stature. Intersex can include things that are invisible to the eye such as chromosomal and hormonal differences. Those kinds of differences usually have a manifestation in primary or secondary sexual anatomy that is visible either externally or internally. Brain differences may account for both homosexuality and transsexualism, but intersex isn’t brain sex alone. We are intersex because it is thought the kinds of differences in our anatomy seem to be either male and female at the same time or not quite male or female or neither male or female. So we have physical differences that confuse medicine’s anatomical ideal of male and female. Intersex is not always immediately apparent because in our society we do not commonly look at each other’s genitals or internal organs.”

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2018-09-02T15:58:50+00:00Categories: 47,XXY (Klinefelter), Other Variations|