What are the Symptoms of XYY Syndrome?

XYY syndrome is a rare chromosomal birth defect found in men. This genetic disorder occurs due to the extra copy of a Y chromosome. Instead of 46 chromosomes, the affected individuals have 47 chromosomes in each or some cells. About 1 in every 1,000 men is found to be affected by this condition. This disorder is caused due to missegregation of chromosomes during cell division of sperm. The real cause of this error is still unknown.

Symptoms of XYY Syndrome

The signs and symptoms of XYY syndrome are often unnoticeable and subtle. In some cases, boys during their infant or teenage state show certain symptoms that vary from person to person. Below given are some of the most common XYY syndrome symptoms:

Physical Traits

There are few physical traits that are visible during the childhood or adolescence of a boy affected by this syndrome. One of the most noticeable XYY symptoms is the increased height than the average height. Also, the affected boys have widely spaced eyes, a larger head dimension and a curved pinky finger. He may also have low muscles tone and severe acne during adolescence.

Cognitive Traits

Usually, boys with XYY symptoms have normal intelligence. However, it is found that the average IQ of boys affected with this syndrome is slightly lower than their siblings. Also, some boys show a delay in reaching the milestones such as walking or crawling. Other signs of XYY syndrome include attention difficulties, speech delays, language problems and reading difficulties.

Behavioral Traits

Men with XYY syndrome may develop behavioral issues such as high temper, hyperactivity, impulsivity, etc. They may be affected by involuntary muscle movements such as hand tremors and motor tics. Also, this syndrome increases the risk of attention deficit and hyperactivity disorder.

Differential Diagnosis

The symptoms of XYY syndrome are similar to Klinefelter syndrome, Marfan syndrome and Sotos syndrome. Let us discuss the same below:

Klinefelter Syndrome

Klinefelter syndrome is when males have an extra pair or X chromosomes. The symptoms of this rare disease are:

Tall stature
Lack of secondary sexual characteristics
Delayed puberty
Small testes
Breast development

Sotos Syndrome

Sotos syndrome is a variable genetic disorder caused by the mutation of the NSD1 gene. The signs and symptoms of Sotos syndrome are:

Abnormally prominent forehead
Taller than average
Greater head circumference
Motor and language development delays
Congenital heart and kidney problems
Increased risk of developing some specific types of tumors

Marfan Syndrome

This is a genetic disorder caused due to the mutation of the fibrillin-1 (FBN-1). It majorly affects the connective tissues that are found in the whole body. Symptoms of Marfan syndrome include: