Turner Syndrome vs Down Syndrome: Difference and Comparison

Key Takeaways

1. Genetic Cause: Turner syndrome is caused by the absence or partial loss of one of the two X chromosomes in females, while Down syndrome results from an extra copy of chromosome 21.
2. Physical Characteristics: Turner syndrome is associated with short stature, a webbed neck, and specific physical features, while Down syndrome is characterized by distinct facial features, such as upward-slanting eyes and a small mouth, along with low muscle tone and shorter stature.
3. Intellectual and Developmental Differences: Girls with Turner syndrome have normal intelligence or mild learning difficulties, whereas individuals with Down syndrome have varying degrees of intellectual disability, ranging from mild to moderate. Early intervention and education support are important for their development.

What is Turner Syndrome?

Turner syndrome is a genetic condition affecting females born with a missing or incomplete X chromosome. Normally, females have two X chromosomes, but those with Turner syndrome have only one X chromosome or one incomplete X chromosome. This can lead to various physical and medical problems, including short stature, delayed puberty, infertility, heart and kidney abnormalities, hearing loss, and learning difficulties.

The symptoms of Turner syndrome can vary from person to person, and not all affected individuals experience the same symptoms. However, early diagnosis and treatment can help manage some of the associated health problems and improve the quality of life for those with Turner syndrome.

What is Down Syndrome?

Down syndrome, or trisomy 21, is a genetic condition when a person has an extra copy of chromosome 21. Normally, people have two copies of this chromosome, but individuals with Down syndrome have three copies, resulting in developmental and physical differences.

The symptoms of Down syndrome can vary from mild to severe, and individuals with Down syndrome may experience some or all of the following features: intellectual disability, delayed development, distinctive facial features, heart defects, hearing and vision problems, and a higher risk of developing certain health conditions such as leukemia and Alzheimer’s disease.

Difference Between Turner Syndrome and Down Syndrome

1. Turner syndrome is caused by a missing or incomplete X chromosome in females, while an extra copy of chromosome 21 causes Down syndrome.
2. Turner syndrome is relatively rare, affecting approximately 1 in 2,500 females, while Down syndrome is more common, affecting about 1 in 700 births worldwide.
3. Individuals with Turner syndrome may have a webbed neck, low hairline, and short stature. In contrast, individuals with Down syndrome have distinctive facial features such as upward-slanting eyes, a flattened nose bridge, and a small mouth.
4. While individuals with Turner syndrome may have some learning difficulties, they have average intelligence, whereas those with Down syndrome have mild to moderate intellectual disabilities.
5. Turner syndrome can be associated with various health complications, such as heart and kidney abnormalities, hearing loss, and infertility. In contrast, individuals with Down syndrome are more prone to heart defects, hearing and vision problems, and a higher risk of developing certain health conditions such as leukemia and Alzheimer’s.

Comparison Between Turner Syndrome and Down Syndrome

Parameters of Comparison	Turner Syndrome	Down Syndrome
Chromosome abnormality	Missing or incomplete X chromosome in females	Relatively rare, it affects approximately 1 in 2,500 females
Prevalence	More common, it affects about 1 in 700 births worldwide	More common, affects about 1 in 700 births worldwide
Physical features	Webbed neck, low hairline, short stature	Distinctive facial features, such as upward-slanting eyes, a flattened nose bridge, and a small mouth
Intellectual disability	May have some learning difficulties, have average intelligence	Often have mild to moderate intellectual disability
Health complications	Heart and kidney abnormalities, hearing loss, and infertility	Prone to heart defects, hearing and vision problems, and a higher risk of developing certain health conditions such as leukemia and Alzheimer’s disease

References

1. https://www.sciencedirect.com/science/article/pii/S105324981831297X
2. https://www.primarycare.theclinics.com/article/S0095-4543(04)00049-1/abstract

Last Updated : 13 July, 2023