A genetic disorder that is the most common cause of inherited intellectual disability and autism spectrum disorders
Fragile X syndrome
Caused by an expansion of a repetitive sequence of DNA called a CGG repeat on the X chromosome
This expansion results in the silencing of the FMR1 gene, which codes for the fragile X mental retardation protein (FMRP)
The absence or dysfunction of this protein leads to various developmental and cognitive challenges
CGG repeat
A repetitive sequence of DNA on the X chromosome
A normal copy of the FMR1 gene has 5-44 CGG repeats, while individuals with Fragile X syndrome have 200 or more repeats</b>
The expansion of the CGG repeat in the FMR1 gene
Interferes with the production of FMRP, resulting in its absence or dysfunction
Fragile X syndrome can affect both males and females
Males with Fragile X syndrome
Typically exhibit more severe symptoms than females because females have two copies of the FMR1 gene (XX), so even if one copy is affected, the other can compensate for its absence or dysfunction to some extent
Klinefelter syndrome
A genetic condition that occurs in males when they have an extra X chromosome, resulting in a chromosomal pattern of XXY instead of the typical XY
Klinefelter syndrome
Can lead to a variety of physical and developmental differences, including infertility, reduced testosterone levels, small testes, gynecomastia (enlarged breasts), and potential learning and behavioral challenges
Klinefelter syndrome is the most common chromosomal disorder in males, occurring in about 1 in every 500 to 1,000 male births
Klinefelter syndrome is characterized by the presence of an extra X chromosome (XXY), which can lead to various physical and developmental differences
Prader-Willi Syndrome (PWS)
A complex, multisystem disorder characterized by neonatal hypotonia with poor suck and poor weight gain without nutritional support, developmental delay, mild cognitive impairment, hypogonadism
Some people with Prader-Willi syndrome have unusually fair skin and light-colored hair
Both affected males and affected females have underdeveloped genitals
Puberty is delayed or incomplete, and most affected individuals are unable to have children (infertile)
Cri du chat syndrome
A rare genetic disorder caused by missing pieces on a particular chromosome
Cri du chat syndrome is not the result of anything the parents have done or failed to do
Characteristics of a newborn with cri du chat syndrome
High-pitched cry
Small head
Flattened bridge of the nose
When the structure of chromosome 5 is changed, it causes cri du chat syndrome
Effects of cri du chat syndrome
Constipation
High rate of infections
Poor muscle tone
Eye problems
Cri du chat syndrome
The babies affected have a high pitched cry, imitating a cat-like sound
Around 1 in 50,000 get diagnosed with cri du chat syndrome
People who are affected by cri du chat syndrome live over 50 years old
75% of people with cri du chat syndrome die in their first month and 90% die in their first year
Down syndrome
A condition in which a baby is born with an extra chromosome number 21
Down syndrome
Associated with delays in the child's mental and physical development
Increased risk for health problems
Down syndrome is not new - the first evidence of its existence dates back 2,500 years</b>
Down syndrome is named after John Langdon Down, an English doctor who published a clinical description in 1866
In the 1940s, a child with Down syndrome had a life expectancy of 12 years
These days, their life expectancy is 60 years and a baby born with Down syndrome could live into their 80s — in line with the general population
Turner syndrome
A condition that affects only females, results when one of the X chromosomes (sex chromosomes) is missing or partially missing
Turner syndrome
Can cause short adult human height
Can cause infertility
Turner syndrome can cause a variety of medical and developmental problems, including short height, failure of the ovaries to develop and heart defects
The life expectancy for people with Turner syndrome might be slightly shorter
By testing for and treating the health conditions that can come with TS, people with TS can expect to have a typical lifespan
Williams syndrome is a rare genetic disorder that is caused by the deletion of genetic material on chromosome 7. Typical characteristics include distinctive facial features, mild intellectual disability and an overly sociable personality.
People with WS may have mild to moderate delays in their cognitive development (ability to think and reason) or learning difficulties. They also may have a distinctive facial appearance, and a unique personality that combines over-friendliness and high levels of empathy with anxiety.
People with WS may have mild to moderate delays in their cognitive development (ability to think and reason) or learning difficulties. They also may have a distinctive facial appearance, and a unique personality that combines over-friendliness and high levels of empathy with anxiety.
Cystic fibrosis is an inherited disease caused by mutations in a gene called the cystic fibrosis transmembrane conductance regulator (CFTR). The CFTR gene provides instructions for the CFTR protein . People who inherit two copies of a mutated CFTR gene (one copy from each biological parent) will have cystic fibrosis.
Cystic fibrosis is called 65 roses because an observant 4-year-old, hearing the name of his disease for the first time, pronounced cystic fibrosis as "65 Roses." Today, "65 Roses" is a term often used by young children with cystic fibrosis to pronounce the name of their disease.