Trisomy X: 47 XXX Female

Sania NaqviDevelopmental Biology Recitation9/14/2015

Karyotype of 47 XXX Female [1]

Background Information

Chromosomal Issue: •Normal female: born with two X chromosomes, one from the mother and one from the father, at chromosome pair 23 [5]

•total number of chromosomes is 46 [5].

•47 XXX Female: born with three X chromosomes (Trisomy) at chromosome pair 23 [5].

•Increase of the total number of chromosomes to 47 [5].

Etiology: Triple X Syndrome occurs via nondisjunction [5].

During meiosis, a pair of chromosomes fails to spilt [4]. This results in the formation of a sperm or egg with an extra chromosome [2].

▪The resulting embryo will, in this case, have three X chromosomes at chromosome pair 23 [2].▪Research shows source is more likely to be maternal [2].

Incidence: 1/1000 girls are born with this genetic disorder [5].

How common is this in America? ▪ For every 10 girls, half will have Trisomy X [5].

[4]

Clinical Information

SIGNS/SYMPTOMS Physical signs:

tall in height [3] decreased muscle tone (hypotonia) [3] inner corners of the eyes have vertical skin folding

(epicanthal folds) [3] curving of the pinky finger (clinodactyly) [3]

Cognitive signs: delays in motor and speech skills set [2] disabilities in learning & socializing [2] decreased self-esteem [2] late onset of maturity [2] Anxiety [2] Mood disorders [2]

Symptoms: decreased fertility [2]

▪ Minority women prone to Premature Ovarian failure [2]; early menopause [2]

▪ However, majority of the women with Trisomy X will be able to reproduce [5]

constipation [3] pain in the abdomen region [3] renal complications [2] seizures [2]

TREATMENT Unfortunately, there is no known

cure [2] Lifestyle modifications:

Therapy for speech and motor skill delays [2]

Anxiety treatment including therapy and medication [2]

Gastrointestinal conditions: female should intake a diet high in fiber [2]. She should also take a laxative and partake in exercise [2]

Educational accommodations: small class size, home school, part time student [2]

References

[1]IUPUI Department of Biology, “Human Chromosomal Disorders”, http://www.biology.iupui.edu/biocourses/N100/2k2humancsomaldisorders.html

[2]Klinefelter Syndrome and Associates, “Frequently Asked Questions Related to Trisomy X (47,XXX),” http://www.genetic.org/Portals/0/Public/Docs/TRISOMY_X_FAQ-8-2-12.pdf

[3] Mayo Clinic, “Triple X Syndrome,” http://www.mayoclinic.org/diseases-conditions/triple-x-syndrome/basics/definition/con-20033705

[4] Penn State Eberly College of Science, “How are Sex Chromosomes Inherited ?,” https://online.science.psu.edu/biol011_sandbox_7239/node/7404

[5] U.S. National Library of Medicine, “Triple X Syndrome,” http://ghr.nlm.nih.gov/condition/triple-x-syndrome