TripleX
Triple X Syndrome
X-Graviton:
Abarquez
Benedian
Dagasdas
Mende
Suico
Definition
Trisomy X is a disorder that affects females and is characterized by the presence of an additional X chromosome.
Triple X Syndrome is also known as:
47, XXX
47, XXX karyotype
47, XXX syndrome
Trisomy X syndrome
Triplo X
What is Triple X Syndrome?
Normally, females have two X chromosomes;
however, females with trisomy
X carry three X chromosomes in the nuclei of body cells.
There are specific physical features (phenotype) associated with this chromosomal disorder.
Symptoms
Tall Stature
Skin folds that descend and cover the inner corners of the eyes
Wide spacing between the eyes
Decreased muscle tone
(hypotonia)
Curved fifth ("pinky") fingers
(clinodactyly)
Small head circumference
Lower average birth weight
Learning disabilities, such as delayed speech and language development, and difficulty reading
Delayed motor skills, such as
sitting and walking
Problems processing sound
Behavioral and emotional problems, including attention deficit hyperactivity disorder
(ADHD), anxiety, and depression
Premature ovarian failure or ovary malformations (though infertility is rare)
Menstrual irregularities
Constipation or abdominal pains
Flat feet
Mild concavity of the breastbone
Increased distance between the eyes in
9 year old girl with trisomy x
The type of finger curvature frequently seen in triple x syndrome
Epicanthal folds and increased distance between the eyes in 2year old girl with trisomy
Symptoms
Seizures or kidney abnormalities (such as having a single kidney, or a malformed one), are possible in triple X but rare — they show up in about 10 percent of cases.
usually of normal intelligence, but IQ scores, especially verbal scores, tend to be 10 to 15 points below that of siblings or those in control groups especially if learning disabilities are not addressed early.
Heart abnormalities have been noted in some isolated cases
Causes
-
Nondisjunction
In most cases, either the mother's egg cell or the father's sperm cell divides incorrectly, resulting in an extra X chromosome in the child. This random error is called nondisjunction, and all the cells in the child's body will have the extra X chromosome.
Causes
Mosaic
- Occasionally, the extra chromosome results from an incorrect cell division caused by a random event early in the embryo's development. If this is the case, the child has a mosaic form of triple X syndrome, and only some cells have the extra X chromosome.
- Females with the mosaic form may have less obvious symptoms.
General Info
This condition occurs in about 1 in
1,000 newborn girls. Five to 10 girls with triple X syndrome are born in the United States each day.
Triple X syndrome can be diagnosed prenatally, through CVS (chorionic villus sampling, in which tissue samples are taken from the placenta) or through amniocentesis.
The condition can also be diagnosed through a postbirth blood test if developmental delays, poor muscle tone, or other physical characteristics associated with triple X prompt a doctor to suspect it.
There is no cure for triple X syndrome, but treatments can help with specific symptoms.
Treatments can include:
Regular doctor visits: At periodic visits, a doctor can monitor a girl's development for delays, social and language disabilities, or health problems and treat these promptly.
Additional Info
Trisomy X is not inherited. It is caused by errors during the normal division of reproductive cells in one of the parents.
In some affected females, only a certain percentage of their cells may have three X chromosomes, while other cells have a normal chromosomal make-up (46,XX/47,XXX mosaicism).
These females may have milder symptoms and fewer developmental and learning problems.
-
-
Researchers believe that the symptoms and physical features associated with trisomy X develop because of overexpression of the genes that escape normal X-inactivation.
Similar abnormalities include:
Tetra X syndrome, a rare chromosomal abnormality in which females have two extra X chromosomes in the nuclei of body cells (48,XXXX karyotype)
Penta X syndrome, an abnormality of the same kind in which females have three extra X chromosomes in the nuclei of body cells (49,XXXXX karyotype)
Sources
https://ghr.nlm.nih.gov/condition/triple-x-syndrome#resources https://www.mayoclinic.org/diseases-conditions/triple-xsyndrome/symptoms-causes/syc-20350977 https://en.m.wikipedia.org/wiki/Triple_X_syndrome https://kidshealth.org/en/parents/triple-x-syndrome.html
https://rarediseases.org/rare-diseases/trisomy-x/
