Turner syndrome
According to the national organization for rare disorders (NORD), Turner syndrome (TS) is a rare genetic disorder due to chromosomal aberrations. Turner syndrome affects the female population. It is featured by a partial or complete deficit of one of the sex chromosomes – the ‘X’ chromosome, leading to a genetic phenomenon called monosomy. Turner syndrome is also known as congenital ovarian hypoplasia. The timely and early diagnosis of girls with Turner syndrome is essential to manage the disease, even though in most cases, the disease is diagnosed late. Prenatal diagnosis is an important way to detect the disease early in life.
Symptoms
The symptoms vary with increasing age. Turner syndrome can manifest with:
Congenital lymphedema of the extremities
Dysplasia of nail
Short stature and webbed neck
Broad chest with widely spaced nipples
Narrow and high-arched palate
Short fourth metacarpals or metatarsals
“Shield” chest
Low hairline at the base of the neck
Cubitus valgus
Madelung deformity of the forearm and the wrist (rare arm condition that affects the growth plate of the radius, a bone in the forearm)
Coarctation of the aorta
Ovarian dysgenesis, delayed puberty, infertility, hypogonadotropic hypogonadism
Congenital malformations of the heart, type 1 as well as type 2 diabetes mellitus, autoimmune disorders, as well as osteoporosis.
Neurocognitive deficits
Diagnosis
The diagnosis relies primarily on the prenatal sampling of chorionic-villus or amniocentesis (removal process of amniotic fluid for testing). An ultrasound signal of the mother’s womb showing signs of fetal hydrops (severe swelling in the fetal stage), cardiac defects, or cystic hygroma (a fluid-filled sac that is an outcome of a blockage in the lymphatic system) should be considered as suspected signs followed by confirmation with karyotype testing. Karyotype testing is the examination of the abnormality of all chromosomes residing within the cells of the patients. A karyotype analysis should be done with peripheral blood mononuclear cells.
Occasionally, the karyotype can be normal if turner syndrome exhibits mosaicism. If there is a strong suspicion even after obtaining normal karyotype testing from different tissues, a FISH or fluorescence in situ hybridization study is performed, in addition to the karyotype, which can detect abnormality even in part of DNA sequence or chromosomes.
In adolescent patients, after birth diagnosis can initiate typical clinical manifestations of delayed puberty onset. Other laboratory test findings confirmatory of Turner syndrome include elevated levels of follicle-stimulating hormone or FSH. Moreover, the anti-Mullerian hormone (AMH) may be a better marker for predicting the clinical feature of ovarian failure in Turner syndrome.
Management
Symptomatic management is the mainstay in the management of TS. The following management approaches are taken:
Short stature management in girls early in their lives with Turner syndrome with growing hormone therapy.
Coarctation (a birth defect with a narrower aorta than usual) of the aorta needs corrective surgery. Persistent monitoring throughout life for aortic dilation in patients is done using cardiac MRI or echocardiogram.
Blood pressure should be maintained with beta-blockers followed by ACE inhibitors and monitored for minimizing the risk of aortic dilation and dissection.
Estrogen replacement therapy should start if no breast development begins by 11 to 12 years of age.
Serial audiology evaluations, every three years in children and every five years in adults, are recommended all through the lifespan of Turner syndrome patients. Intensive patient education, vaccinations, and antibiotic treatment are needed in high-risk hearing disability groups.
In case of renal abnormalities, the patient should be referred to a nephrologist for renal evaluation.
The bone mineral density degradation risk can be reduced with estrogen therapy and supplemental calcium and vitamin D.
Medical and integrative therapeutic advice should be given to motivate patients including physical exercise and refraining from bad habits such as smoking.
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