Males with one DHH gene variant may also be unaffected, or they may have genital differences such as the urethra opening on the underside of the penis hypospadias.
Genetics Home Reference has merged with MedlinePlus. Learn more. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. Swyer syndrome. From Genetics Home Reference. Description Swyer syndrome is a condition that affects sex development.
Frequency Swyer syndrome occurs in approximately 1 in 80, people. Causes In most individuals with Swyer syndrome, the cause is unknown. Inheritance Most cases of Swyer syndrome are not inherited; they occur in people with no history of the condition in their family. DSDs: genetics, underlying pathologies and psychosexual differentiation. Nat Rev Endocrinol. Epub Aug 5. Translational genetics for diagnosis of human disorders of sex development.
Annu Rev Genomics Hum Genet. Epub Jul Steroidogenic factor-1 and human disease. Semin Reprod Med. Epub Oct 8. Curr Opin Endocrinol Diabetes Obes. Hum Mol Genet. Epub Oct Review and management of 46,XY disorders of sex development.
J Pediatr Urol. Epub Dec Swyer syndrome: presentation and outcomes. Nonsyndromic Disorders of Testicular Development. Furthermore, a case of a female who had shown complete testicular feminization and 47,XXY karyotype was reported by Gerli et al [ 6 ]. However, the report did not show the presence of Yp deletion or SRY deletion, and it concluded that the testicular feminization was due to the androgen insensitivity syndrome [ 6 ]. A 7-yr, 9-mo-old girl was referred to the pediatric endocrinology service due to early development of the breasts and acceleration of growth.
The girl, who had a birth weight of 3. Her father was cm tall 50—75 percentile and her mother was cm tall 5—10 percentile. Both were phenotypically normal.
The patient was Pubertal development evaluation by the Marshall-Tanner method [ 7 ] revealed breast stage 2—3 and pubic hair stage 1. Her fourth and fifth metacarpal bones were short. There were no other abnormalities on physical examination. Her bone age was around mo. Pelvic ultrasonography showed the size of the uterus uterine volume, 1. Although the patient had signs of precocious puberty eg, breast development before the age of 8 yr and advanced bone maturation , her levels of estradiol, LH, and FSH indicated her to be at an early stage of precocious puberty.
The patient is being followed every 6 mo and is not receiving any treatment. Chromosomes were prepared from a hr peripheral blood culture. Standard procedures for cultures, harvests, and slide preparation were modified and performed in our laboratory. The cultured cells were then exposed to colcemid for 20 min, followed by 30 min of hypotonic treatment KCl. A fixation procedure with ethanol and acetic acid 2. The probes were hybridized to metaphase cells; images were captured with a Cytovision Image Analyzer Applied Imaging International, Newcastle, England and seven metaphases were analyzed.
Instead of the genomic DNA, deionized water was added for a negative control. The amelogenin gene on the X chromosome bp and amelogenin -like sequence on the Y chromosome bp were amplified by using primers designed by Nakadori et al [ 11 ]. By G-banding analysis, an enlarged short arm of chromosome 22 consisting of an heterochromatic component was detected Fig.
The additional material attached to chromosome 22p was shown by metaphase fluorescence in situ hybridization FISH with whole chromosome painting probes as being derived from the Y chromosome Fig. Giemsa-banding karyogram of the peripheral blood of the patient: 46,XX,der Y;22 q10;q The derivative chromosome t Y;22 is indicated by an arrow. Partial karyogram of the father of the patient showing satellited Y resulting in t 22;Y. The derivative chromosome t Y;22 , which resembles that of the daughter, is indicated by an arrow.
In PCR analysis for the amelogenin gene, the patient and the female control showed a PCR product of bp only, while the male control showed two separate bands of bp and bp, indicating absence of the amelogenin -like sequence in our patient Fig. This finding means that the patient is missing not only the distal part of the Yp but also the proximal part. The figure shows absence of A sex determining region Y bp and B amelogenin -like sequence bp in the patient.
The amelogenin sequence on the X chromosome, which has an additional bp insert, was present in the patient and in the female and male controls. Her father showed 46,XY,der Y;22 q10;q10 , which revealed that the derivative chromosome was descended from her father Fig.
But men with Klinefelter syndrome are at a slightly increased risk of developing other health problems, including:. These problems can usually be treated if they do occur and testosterone replacement therapy may help reduce the risk of some of them.
This chromosome carries extra copies of genes, which interfere with the development of the testicles and mean they produce less testosterone male sex hormone than usual. The extra genetic information may either be carried in every cell in the body or it may only affect some cells known as mosaic Klinefelter syndrome. Klinefelter syndrome is not directly inherited — the additional X chromosome occurs as a result of either the mother's egg or the father's sperm having the extra X chromosome an equal chance of this happening in either , so after conception the chromosome pattern is XXY rather than XY.
This change in the egg or sperm seems to happen randomly. If you have a son with the condition, the chances of this happening again are very small. But the risk of a woman having a son with Klinefelter syndrome may be slightly higher if the mother is over 35 years of age. See your GP if you have concerns about your son's development or you notice any troubling symptoms of Klinefelter syndrome in yourself or your son.
Klinefelter syndrome is not necessarily anything serious, but treatment can help reduce some of the symptoms if necessary. Your GP may suspect Klinefelter syndrome after a physical examination and may suggest sending off a sample of blood to check reproductive hormone levels. The diagnosis can be confirmed by checking a sample of blood for the presence of the extra X chromosome. There's no cure for Klinefelter syndrome, but some of the problems associated with the condition can be treated if necessary.
TRT involves taking medicines containing testosterone.
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