47, XXX Syndrome

Myths about 47,XXX (and why they are just myths!)

Girls with 47,XXX have below-average IQs and are thus not capable of higher education.

While the combination of reading dysfunction and language-based learning disorders lower the IQs of girls with 47,XXX, when given appropriate services they can attend college and pursue various careers.

There is an increased incidence of ADHD in the 47,XXX population.

It has been reported that ADHD is present in 25-35% of this population [Bender et al., 1993; Pennington et al., 1980], however ascertainment bias means the true number is likely lower. This is because the more severe cases of 47,XXX tend to be diagnosed while the minimally impaired girls are not diagnosed (and are thus not included in such studies).

Girls with 47,XXX cannot have children.

Women with 47,XXX are known to have successful pregnancies and healthy babies, though there is an increased incidence of Premature Ovarian Failure (POF).

THE FACTS

With as many as 1 in 900 girls having 47, XXX, millions of affected girls are undiagnosed.

There is equal distribution of 47, XXX across all racial and socio-economic groups.

More than 750,000 people are believed to have X & Y chromosomal aneuploidies in the United States alone.

Girls that are prenatally diagnosed and receive early intervention service typically present with fewer and less severe cognitive disabilities.

47, XXX girls are typically in the highest height percentiles for their respective age groups.

Girls consistently present with language-based learning disabilities and motor planning issues that are related to the high rates of dyspraxia and dyslexia associated with the disorder.

In the majority of cases the primary cause for dyslexia and dyspraxia is unknown, however 47, XXX may be the root for many of these girls’ deficits.

· Girls with 47, XXX have an increased incidence of anxiety, suspected to present as early as 7 years of age with some showing signs of anxiety disorders as young as preschool.

Our X & Y Disorder Research

The Focus Foundation’s efforts are geared toward X & Y Chromosomal Variations including: 47, XXY (Klinefelter syndrome), 47, XYY (Jacob’s syndrome), 47, XXX (Triple X), 48, XXXX (Tetrasomy X), 48, XXXY, and 49, XXXXY. For further information on Klinefelter syndrome, Jacob’s syndrome, and some of the less commonly occurring X and Y disorders, click on the links that follow:

47,XXY (occurs in 1 out of 650 live births)

Only 25% of males with 47,XXY are ever diagnosed during their lifetimes; fewer than 10% of 47,XXY individuals are identified prior to adolescence. This means that millions of affected children remain undiagnosed–often because they are commonly misdiagnosed as simply having speech or motor delays. More than 500,000 people are believed to have 47,XXY disorders in the United States alone, with an equal distribution across all racial and socio-economic groups.

Testosterone replacement has been shown to have a positive impact on brain function through 9 years of age in multiple research studies over the last 20 years. Thus, it is important to consider early hormonal replacement therapy (EHT) for 47,XXY boys who experience decreased testosterone production during critical developmental periods.…READ MORE

47,XYY (occurs in 1 out of 1,000 live births)

At least 85% of those with 47,XYY are never diagnosed. 47,XYY boys consistently present with language-based Learning Disabilities and difficulties with Motor Planning–both issues that are related to the high rate of dyspraxia and dyslexia associated with the disorder. However, 47,XYY boys are commonly misdiagnosed as simply having speech or motor delays.

Boys with 47,XYY typically reach an average height of between 6’3” and 6’5”…READ MORE

47,XXX (occurs in 1 out of 900 live births)

As many as 1 in 900 girls have 47,XXX. Unfortunately, millions of affected girls are undiagnosed. Girls who are prenatally diagnosed and receive early intervention services typically exhibit fewer and less severe cognitive disabilities.

There is an equal distribution of 47,XXX across all racial and socio-economic groups…READ MORE

48,XXYY (occurs in 1 out of 18,000 live male births)

Boys with 48,XXYY consistently exhibit Language-Based Learning Disabilities (LLD) and difficulties with Motor Planning, issues that are related to the high rate of dyslexia associated with the disorder. However, they seem to be stronger in math and such visual-spatial activities as assembling puzzles or remembering directions.

Intellectual disabilities are common in 48,XXYY, with average full-scale IQs in the range of 70-80. Verbal IQs are seen to be significantly lower than performance IQs, due to language-based learning difficulties…READ MORE

48,XXXX (100 cases have been reported)

48,XXXX (also known as Tetrasomy X or Tetra X) is a rare sex chromosome disorder that was first identified in the early 1960s. Since that time, approximately 100 cases have been reported, although less than 50 are described in scientific literature. Due to the scarcity of this female chromosomal variation, it is difficult to define a common phenotypic presentation. A lack of congenital malformations, mild dysmorphology, and varied developmental trajectory suggests that 48,XXXX is largely underdiagnosed…READ MORE

48,XXXY (occurs in 1 in 18,000 to 1 in 40,000 male births)

48,XXXY can result from meiotic or mitotic nondisjunction (errors in chromosomal separation) and is often considered a variant of Klinefelter syndrome (47,XXY). However, boys with 48,XXXY often exhibit a more complicated neurodevelopmental profile than boys with 47,XXY…READ MORE

49,XXXXY (occurs in 1 in 85,000 to 1 in 100,000 live male births)

The first case of 49,XXXXY syndrome was reported in the 1970s, and this chromosomal variation remains one of the rarest sex chromosome disorders. 49,XXXXY results from nondisjunction (errors in chromosomal separation) of the X chromosome occurring during both Meiosis I and Meiosis II…READ MORE

49,XXXXX Pentasomy X (40 females reported since 2011)

Penta X Syndrome is an extremely rare chromosomal disorder that only affects females. While girls normally only have two X chromosomes, girls with Penta X have five X chromosomes. As of 2011, less than 40 cases have been reported.…READ MORE

Klinefelter Syndrome & Other Names You May hear

X & Y Chromosomal Variations are a neurogenetic disorder referred to by many other names, including Sex Chromosome Disorders, X & Y Chromosomal Variations, Sex Chromosome Anomaly, and Sex Chromosome Aneuploidy Variations. (Aneuploidy refers to a number of chromosomes besides 46, the standard number in humans.) The sub-categories that exist within X & Y Chromosomal Variations are identified by names that include 47, XXY (Klinefelter syndrome), 47, XYY (Jacob’s syndrome), 47, XXX (Triple X), 49, XXXXY, Tetrasomy X, Pentasomy X, 49, XXXXXX, and 48, XXXY.

What You Can Do Now

If you have received a prenatal diagnosis indicating that your child has an X & Y chromosomal variation, or feel that your son or daughter is experiencing developmental delays or developmental dysfunction, the following options are designed to help you take the next step in securing appropriate treatment or an early diagnosis.

RESEARCH

Take The Child Questionnaire
QUESTIONNAIRE

DIAGNOSIS

Learn About Chromosomal Microarray
CHROMOSOMAL TESTING

TREATMENT

Syndrome-specific Therapy
ARRANGE A CONSULTATION
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