X & Y Chromosomal Variations
X & Y Chromosomal Variations Are Common But Frequently Undiagnosed
The Focus Foundation is the first and only research-based non-profit foundation exclusively dedicated to identifying and helping children who have X & Y Chromosomal Variations, Dyslexia, Developmental Dyspraxia. The X & Y Variations include 47, XXY OR Klinefelter Syndrome, 47, XYY (Jacob’s Syndrome) , 47, XXX (Triple X).
There are several variant disorders which include Tetrasomy X, Pentasomy X, 49, XXXX, 48, XXXY, 48, XXYY, and 49, XXXXY. Although Physicians, ancillary health care providers and Physical and Occupational Therapists as well as Speech and Language Pathologists are taught that genetic abnormalities typically impact on a child’s neurodevelopmental progression, practitioners often receive insufficient information about X and Y chromosomal disorders or information may be outdated or inaccurate.
The Focus Foundation’s research efforts are committed to educating health professionals throughout the world regarding X and Y Chromosomal Variations, dyslexia and developmental dyspraxia. All three disorders are common but rarely identified and early treatment promotes recovery and optimal development. Therefore, identifying and treating these children is very important for them and their families.
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.
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:
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
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
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
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 (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 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
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
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.