Physical Traits
47,XYY boys have an increased growth velocity from early childhood, with an average final height approximately 7 cm (3") above expected final height. In Edinburgh, Scotland, eight 47,XYY boys born 1967–1972 and identified in a newborn screening program had an average height of 188.1 cm (6'2") at age 18—their fathers' average height was 174.1 cm (5'8½"), their mothers' average height was 162.8 cm (5'4"). The increased gene dosage of three X/Y chromosome pseudoautosomal region (PAR1) SHOX genes has been postulated as a cause of the increased stature seen in all three sex chromosome trisomies: 47,XXX, 47,XXY, and 47,XYY.
Severe acne was noted in a very few early case reports, but dermatologists specializing in acne now doubt the existence of a relationship with 47,XYY.
Testosterone levels (prenatally and postnatally) are normal in 47,XYY males. Most 47,XYY males have normal sexual development and usually have normal fertility.
Read more about this topic: XYY Syndrome
Famous quotes containing the words physical and/or traits:
“I became the Incredible Shrinking Mother the year they started junior high. If our relationship today depended on physical clout, I would have about the same influence with them that the republic of Liechtenstein has on world politics.”
—Mary Kay Blakely (20th century)
“And, beholding in many souls the traits of the divine beauty, and separating in each soul that which is divine from the taint which it has contracted in the world, the lover ascends to the highest beauty, to the love and knowledge of the Divinity, by steps on this ladder of created souls.”
—Ralph Waldo Emerson (1803–1882)