Introduction

Klinefelter syndrome is a chromosomal genetic disorder in which men and persons assigned male at birth have an extra X chromosome in their genetic code. In a physiologically normal male, there are 46 chromosomes (46, XY). However, individuals with Klinefelter syndrome a total of 47 chromosomes (47, XXY).

It is also referred to as XXY syndrome.

This article focuses on Key Facts & Statistics, Causes & Types, Signs & Symptoms, Diagnostic Procedures & Tests, Treatment and Management, Complications, Prevention of XXY syndrome.

 

 Key Facts & Statistics

What are the key facts and statistics about Klinefelter syndrome?

• The condition is quite common. 1 in 600 men and persons assigned male at birth have Klinefelter syndrome.
• It is estimated that nearly 80% of all these people do not know they have Klinefelter syndrome.
• It is a congenital disorder.

Causes & Types

What are the causes of Klinefelter syndrome?

Klinefelter syndrome results when there is an additional X chromosome to the genetic code of an individual.

It occurs before birth, in any of the following ways:

• Sperm cell containing an additional X chromosome.
• Egg cell with an additional X chromosome.
• Incorrect cell division during early fetal development (mosaic Klinefelter syndrome- some of the cells have an extra X chromosome).

 

Types

Men and individuals assigned male at birth who have Klinefelter syndrome may have:

• An additional X chromosome in each cell (this is the most common).
• Mosaic Klinefelter syndrome, where only some cells have an extra X chromosome.
• More than 1 additional X chromosome. This form is rare, but severe.

 

 Signs & Symptoms

What are the signs and symptoms of Klinefelter syndrome?

In babies and infants:

• Hernia.
• Slower learning of how to sit up, crawl and talk (speech delay).
• Undescended testicles.
• Weaker muscles.

 

In children:

• Low energy levels.
• Learning difficulties.
• Poor social interactions.
• Attention-deficit/hyperactivity disorder.
• Low self-esteem.

 

Teenagers and adolescents:

• Larger than normal breasts (gynecomastia).
• Less facial and body hair.
• Absent or delayed puberty.
• Small penis size.
• Relatively taller height, with longer upper and lower limbs but with a shorter trunk.

 

Adults:

• Low libido.
• Low levels of testosterone due to testiscular failure.
• Infertility.
• Poor and weak erections.

 

 Diagnostic Procedures & Tests

How is Klinefelter syndrome diagnosed?

The method used to diagnose Klinefelter syndrome depends on the stage of development: fetal development, childhood or adolescence and adulthood.

 

Fetal development

While conducting tests such as amniocentesis for other health reasons (not with the intention of diagnosing XXY syndrome), the condition may be detected.

 

Childhood or adolescence

Testing is recommended usually when a physician notices atypical growth and development during childhood and teenage.

 

Adulthood

For individuals with fertility issues or low levels of testosterone, a  Klinefelter test is conducted.

 

Testing. Karyotyping is the most common method detecting and identifying an additional X chromosome.

 

 Treatment and Management

Does Klinefelter syndrome have a cure?

There is no cure for Klinefelter syndrome.

 

How is Klinefelter syndrome treated?

Treatment strategies may include:

• Hormone replacement.
• Therapy.
• Treating other health conditions.
• Surgical procedures, although they are rarely done.

 

Hormone replacement

• In Klinefelter syndrome, there is low levels of testosterone. Replacing this important hormone can help in reducing symptoms.
• This strategy is aimed at;

1. Strengthening the bones.
2. Raising libido.
3. Deepening the voice.
4. Improving mood and self-image.

 

Therapy

• Types of therapy for XXY syndrome include:

1. Occupational therapy.
2. Physical therapy.
3. Speech-language pathology.

 

Surgical procedures

A good example is gynecomastia surgery, where additional breast tissues are removed.

 

 Complications

What are the complications of Klinefelter syndrome?

Men and persons AMAB who have Klinefelter syndrome have a slightly increased chance of developing other medical conditions:

• Metabolic disorders such as:

1. Type 2 diabetes.
2. Obesity.

• Seizure disorders.
• Autoimmune conditions such as:

1. Rheumatoid arthritis.
2. Type 1 diabetes.
3. Lupus.

• Osteoporosis.
• Male breast cancer.
• Gynecomastia.
• Tremors.
• Learning difficulties.
• Hypothyroidism.

 

Prevention

How do we prevent Klinefelter syndrome?

• XXY syndrome occurs due to random alterations in the genetic code during pregnancy. Therefore, it is not preventable.
• The good news is that XXY syndrome is not an inheritable condition.
• The bad news is that there is nothing that can be done by parents to prevent their child from developing this condition.