-Turner Syndrome.

Turner Syndrome

*Def :- It is a condition in which a female has only one X sex chromosome instead of XX in her cells (i.e XO or monosomy ) (1).

*Synonyms:-

• Ullrich-Turner syndrome.
• Gonadal dysgenesis (2).
  

*Pathophysiology:-
- Most commonly due to non-disjunction of chromosome X during formation of ova so ovum with one X chromosome when fertilized an by sperm carrying X chromosome give baby with XO.
- It occurs also in normal ovum when fertilized with sperm neither X nor Y .

* Although in females,only one X chromosome is active , the presence of two X chromosomes is essential for development of the ovaries (1).

*Karyotype (1) :- 45,XO

*Buccal smear:- -ve Barr's body.

*Hormonal assay:- decrease sex hormones.

* Clinical picture (1):-

• Short stature ( most common presentation).
  
• Lymphedema (swelling) of the hands and feet
• Broad chest (shield chest) and widely-spaced nipples
• Low hairline
• Low-set ears
• infertility ( due to ovarian dysgenesis)
• Amenorrhea, or the absence of a menstrual period
• Increased weight, obesity
• Shield shaped thorax of heart
• Shortened metacarpal IV (of hand)
• Small fingernails
• Characteristic facial features (e.g hypertelorism,epicanthic fold,narrow maxilla)
  
• Webbed neck from cystic hygroma in infancy.
• Congenital heart diseases in 35% of cases mainly Coarctation of the aorta.
• Poor breast development.
• Congenital renal diseases (e.g Horseshoe kidney).
• Cubitus valgus ( wide carrying angle).
  
• Mental development is subnormal "but intelligence is normal".
  

*Prognosis:-

While most of the physical findings in Turner syndrome are harmless, there can be significant medical problems associated with the syndrome.

*Treatment:-

As a chromosomal condition, there is no cure for Turner syndrome. However, much can be done to minimize the symptoms. For example:-(3)

• Growth hormone, either alone or with a low dose of androgen, will increase growth and probably final adult height. Growth hormone is approved by the U.S. Food and Drug Administration for treatment of Turner syndrome .(3)
• Estrogen replacement therapy at 14-15 years has been used since the condition was described in 1938 to promote development of secondary sexual characteristics.Estrogens are crucial for maintaining good bone integrity and tissue health (3).
  

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*References:-

(1) Principles of histology vol1,staff members ,faculty of medicine,mansoura university,ch3,p.g76.

(2)James, William; Berger, Timothy; Elston, Dirk (2005). Andrews' Diseases of the Skin: Clinical Dermatology. (10th ed.). Saunders. ISBN 0721629210.
(3)Turner Syndrome Society of the United States. "FAQ 6. What can be done? Retrieved 2007-05-11.