Trisomy X syndrome, or 47, XXX, develops in approximately 1 in 1000 girls but is yet to be diagnosed in many patients. The cause remains unknown, and various physical, intellectual, motor, cognitive and hormonal features may be encountered, although an asymptomatic course is common. The diagnosis can be made either prenatally or postnatally through chromosomal analysis.
Presentation
The clinical course of trisomy X syndrome is variable, with many girls and women being asymptomatic from birth and throughout childhood [1] [2]. This may be one of the reasons why estimates suggest that only 10% of individuals having this mutation are clinically diagnosed [2]. However, numerous features are encountered in different age periods [1] [2] [3] [4]:
- Physical changes - Many neonates exhibit a lower birth weight than normal, accompanied by a normal or reduced head circumference [3]. On the other hand, increased height that is noted from birth, and accelerated growth throughout childhood and puberty, is one of the most common symptoms encountered in trisomy X syndrome [1] [2] [3]. Additional findings include the presence of epicanthal folds, hypertelorism, pes planus, pectus excavatum, clinodactyly and mandibular defects (prognathism and retrognathism) in rare cases [2] [3]. Hypotonia, as a result of mildly affected motor development, is also an important finding.
- Sexual and reproductive phenomena - Most patients have a normal pubertal development, but either precocious or delayed puberty, as well as recurrent miscarriages, ovarian or uterine dysgenesis and premature ovarian failure (POF), have been documented [1] [2].
- Cognitive and intellectual abnormalities - A variable degree of intellectual impairment, in addition to tall stature, is another key feature of trisomy X syndrome. Both verbal and performance IQ can be reduced in older children and teenage girls [3]. Difficulties in language skills are encountered as well [3]. In fact, children who experience learning difficulties, often require special education and early recognition of the disorder may significantly aid in reducing the IQ deficit [3].
- Psychological symptoms - Attention deficit accompanied by anxiety, mood changes, various adjustment disorders, and even psychotic disorders distinguished by paranoia are not uncommon, while social immaturity due to cognitive and intellectual impairment often leads to difficulties in forming relationships, irritability, and even aggression.
It is important to mention that structural organ abnormalities of the kidney (unilateral kidney and renal dysplasia) and the heart (atrial or ventricular septal defects, coarctation of the aorta and pulmonic stenosis) have been observed in a small, but a significant portion of patients [2] [3].
Entire Body System
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Atrial Septal Defect
With that being said, more than half of babies with mosaic trisomy 16 will have fetal abnormalities, including musculoskeletal defects, distinctive facial features, undersized lungs, and an atrial septal defect (a hole between the upper chambers of the [verywell.com]
Psychiatrical
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Indecisiveness
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Neurologic
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Delayed Development of Motor Skills
Females with the condition may have menstrual irregularities, and, although rarely exhibiting severe mental impairments, have an increased risk of learning disabilities, delayed speech, deficient language skills, and delayed development of motor skills [susans.org]
development of motor skills such as language and speech Learning difficulties like dyslexia Proportionately smaller head size or microcephaly Introvert Enamel Hypoplasia Kyphosis Small mandible Low weight in comparison with their height Lordosis Mental [syndromespedia.com]
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Neglect
Key Features: Provides thorough information on understanding functional neuroanatomy and development, and on using functional neuroimaging Highlights clinical practice issues, such as legal and ethical decision-making, dealing with child abuse and neglect [books.google.de]
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Muscle Tone Abnormalities
tone Abnormally curved pinky fingers Vertical folds that cover inner corners of eyes Behavioral and emotional problems Occasionally, some of the following signs and symptoms may occur: Premature ovarian failure Infertility, early or late puberty Constipation [findatopdoc.com]
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Slow Speech
The condition has various effects such as learning difficulties, slow speech development, and muscle weakness. Also, females tend to be taller than the average height. [teaching.ncl.ac.uk]
Workup
The diagnosis of trisomy X syndrome can be difficult to make if symptoms are mild or even absent, which is commonly the case. However, the physician must develop clinical suspicion toward this frequently undiagnosed syndrome in the setting of tall stature that is not supported by parental height, intellectual or psychosocial symptoms, and the presence of other typical features. For this reason, a detailed patient history, and physical examination are the most important parts of workup that will enable the physician to make a presumptive diagnosis. Increased maternal age (estimated around 33 years) is commonly observed in children who subsequently develop trisomy X syndrome, and further information regarding birth weight, as well as growth and development of girls throughout childhood by parents can be of essential importance [3]. Because several genitourinary and cardiac structural diseases have been diagnosed in trisomy X patients, ultrasonography of the abdomen and heart, respectively, should be performed. Moreover, magnetic resonance imaging (MRI) of the brain and electroencephalography (EEG) are recommended during workup, but apart from a reduced brain volume, they yield normal findings in virtually all patients [2] [3]. Genetic studies are necessary to make the diagnosis [1]. Analysis of the karyotype in cells will show an additional X chromosome, and the same finding can be identified prenatally when chorionic villus sampling (CVS) or amniocentesis can detect changes in the number of chromosomes [1] [2].
Serum
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Karyotype Abnormal
Triple X can be diagnosed by a blood test which is able to look at a person’s chromosomes (karyotype). Abnormalities on the electroencephalography may be present. [reliawire.com]
Treatment
Treatment There is no specific treatment for triple X syndrome; many doctors do not consider it a major disability. [encyclopedia.com]
Treatment Options for Triple X Syndrome There is no treatment for triple X syndrome itself because it’s not possible to remove the “spare” X chromosome. [healthpedian.org]
Depending on which symptoms a girl has and how severe they are, doctors may recommend various treatments. What Causes Triple X Syndrome? Girls who have triple X syndrome are born with it. [m.kidshealth.org]
TRIPLE X SYNDROME TREATMENT Treatment for Triple X Syndrome is symptomatic depending on the features of an individual. [evolvegene.com]
Prognosis
The prognosis of persons diagnosed with triple x syndrome is good if they have parents who support them and love them unconditionally. [syndromespedia.com]
ADHD) Weak muscle tone Anxiety or mood disorders Normal sexual development TRIPLE X SYNDROME PROGNOSIS Triple X Syndrome has a favorable prognosis. Most individuals with Triple X Syndrome have mild features of the disorder. [evolvegene.com]
Prognosis The prognosis for girls with triple X syndrome is generally good, particularly if their parents are loving and supportive. They are not at increased risk of other diseases as far as is known and have a normal life expectancy. [encyclopedia.com]
[…] the condition, then genetic counseling will help assess risks, before planning for a child Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders What is the Prognosis [dovemed.com]
Etiology
Each chapter addresses signs and symptoms (including onset and developmental course); epidemiology and etiology (including known genetic and environmental contributors, biological mechanisms and relevant animal models); diagnostic criteria; differential [books.google.de]
(Etiology) Normally, the female sex has XX chromosome, with a single X chromosome being obtained from each parent. [dovemed.com]
Epidemiology
Each chapter addresses signs and symptoms (including onset and developmental course); epidemiology and etiology (including known genetic and environmental contributors, biological mechanisms and relevant animal models); diagnostic criteria; differential [books.google.de]
Pathophysiology
Pathophysiology Cognitive, behavioral, and neuropsychological difficulties characterize the syndrome. [1] These signs are especially important in alerting physicians, parents, and teachers to deficits exhibited by preschool-aged children and elementary [emedicine.medscape.com]
Prevention
Your Trisomy X Syndrome Disability Case If you are disabled because of Trisomy X Syndrome that is so severe it prevents you from working, you may well be entitled to Social Security Disability benefits. [disability-benefits-help.org]
Prevention of Triple X Syndrome Since triple X syndrome is caused by a random chromosomal abnormality, it is not possible to prevent it. [healthpedian.org]
The SSA awards disability benefits to help people whose medical impairments prevent them from working. To speed up their evaluation process, the SSA maintains a list of the medical conditions it considers disabling. [socialsecuritylawcenter.info]
Assistance and support: If the patient is suffering from slow development due to this syndrome, then she should be provided with assistance and support to carry out daily activities. 7 Prevention No preventive measure are available for triple X syndrome [findatopdoc.com]
References
- Afshan A. Triple X syndrome. J Pak Med Assoc. 2012;62(4):392-394.
- Tartaglia NR, Howell S, Sutherland A, Wilson R, Wilson L. A review of trisomy X (47,XXX). Orphanet J Rare Dis. 2010;5:8.
- Otter M, Schrander-Stumpel CT, Curfs LM. Triple X syndrome: a review of the literature. Eur J Hum Genet. 2010;18(3):265-271.
- Otter M, Schrander-Stumpel CT, Didden R, Curfs LMG. The psychiatric phenotype in triple X syndrome: New hypotheses illustrated in two cases. Dev Neurorehabil. 2012;15(3):233-238.