DiGeorge Syndrome – Symptoms and Causes

ByJanis Updated

Overview

DiGeorge syndrome, also called 22q11.2 deletion syndrome, happens when a small piece of chromosome 22 is missing. This genetic condition affects how different body systems grow and work.

The 22q11.2 deletion syndrome includes what doctors once thought were separate conditions. These included DiGeorge syndrome and velocardiofacial syndrome, among others. While they share the same genetic cause, symptoms may differ slightly between people.

Common medical issues linked to this condition include:

  • Heart defects
  • Weakened immune system
  • Cleft palate
  • Low calcium levels
  • Various eye problems
  • Autoimmune disorders

People with this syndrome might also experience:

  • Hearing loss
  • Bone and skeletal differences
  • Kidney problems
  • Genital differences
  • Delayed development
  • Behavioral and emotional challenges

The symptoms vary greatly from person to person in both number and severity.

Almost everyone with 22q11.2 deletion syndrome needs care from different medical specialists to manage their specific symptoms and health needs.

Signs and Symptoms

DiGeorge syndrome presents with a wide range of symptoms that vary in severity from person to person. Some symptoms appear at birth, while others develop later in infancy, childhood, or even adulthood.

Heart Problems

  • Structural heart defects
  • Heart murmurs
  • Bluish skin (cyanosis) due to poor blood circulation

Immune System Issues

  • Frequent infections due to weakened immunity

Facial Features

  • Underdeveloped chin
  • Distinctively shaped ears
  • Wide-set eyes
  • Hooded eyes
  • Enlarged nose tip
  • Asymmetric crying (one side of mouth droops when crying)

Mouth and Feeding Issues

  • Cleft palate (gap in the roof of mouth)
  • Difficulty feeding
  • Failure to gain weight
  • Digestive problems

Muscle and Bone Concerns

  • Poor muscle tone
  • Scoliosis (curved spine)

Developmental Issues

  • Delayed growth
  • Missed infant milestones (rolling over, sitting up)
  • Speech delays
  • Nasal-sounding speech
  • Learning difficulties
  • Behavioral problems

Other Physical Symptoms

  • Low blood calcium levels
  • Kidney problems
  • Hearing loss
  • Vision problems and other eye issues

The symptoms vary in severity and can appear at different stages of life.

Causes

DiGeorge syndrome happens when part of chromosome 22 is missing. This missing segment contains about 30-40 genes in a region called 22q11.2. Scientists still don’t fully understand many of these genes and their functions.

Most cases occur randomly during conception. The deletion typically happens in either:

  • The father’s sperm
  • The mother’s egg
  • Early stages of fetal development

In rare cases, DiGeorge syndrome can be inherited. A parent who has the same chromosome deletion might pass it to their child. These parents often have milder symptoms or fewer health problems related to the condition.

Each person normally has two copies of chromosome 22, with one inherited from each parent. When someone has DiGeorge syndrome, one of these copies is missing this important segment, which affects development and causes the characteristic symptoms of the condition.

Risk Factors

Children who lack a specific part of chromosome 22, called region 22q11.2, face the highest risk of developing DiGeorge syndrome. This genetic deletion affects how different body systems form during early development.

When this small piece of genetic material is missing, it causes poor development across multiple areas of the body. The absence of this chromosome section explains why affected children show various physical and developmental problems.

Complications

DiGeorge syndrome, also known as 22q11.2 deletion syndrome, can affect many body systems during fetal development. These effects can lead to several medical complications.

Heart Defects

Heart problems are common in this syndrome. These may include:

  • Ventricular Septal Defect: A hole between the lower heart chambers.
  • Truncus Arteriosus: A single large blood vessel leaving the heart instead of two.
  • Tetralogy of Fallot: A combination of four different heart structural problems.

These heart issues can reduce the amount of oxygen-rich blood circulating in the body.

Calcium Regulation Problems

The syndrome often affects the parathyroid glands, which may be smaller than normal. This causes:

  • Low production of parathyroid hormone
  • Reduced calcium levels in the blood
  • Elevated phosphorus levels

This condition is called hypoparathyroidism and requires careful management.

Immune System Deficiencies

The thymus gland, which helps T cells mature, may be small or missing entirely. This leads to:

  • Poor immune function
  • Frequent infections
  • More severe illnesses when infections occur

Children with this syndrome often need special care to prevent and treat infections.

Oral Structure Abnormalities

Many affected individuals have structural problems with their mouth and palate:

  • Cleft palate (opening in the roof of the mouth)
  • Cleft lip in some cases
  • Other less visible palate abnormalities

These issues can cause difficulties with swallowing and speech development.

Distinctive Facial Features

Some people with the syndrome have characteristic facial features, including:

  • Small, low-set ears
  • Shortened eye openings
  • Hooded eyes
  • Relatively long face
  • Enlarged nose tip
  • Short or flattened groove in the upper lip

Developmental and Mental Health Issues

Brain development and function may be affected, resulting in:

  • Speech delays in early childhood
  • Learning difficulties
  • Social and developmental challenges
  • Higher rates of ADHD and autism spectrum disorder

As affected individuals grow older, they face an increased risk of depression, anxiety, and other mental health conditions.

Autoimmune Disorders

People with this syndrome have a higher likelihood of developing autoimmune conditions such as:

  • Rheumatoid arthritis
  • Graves’ disease
  • Other disorders where the immune system attacks healthy tissues

Additional Medical Concerns

Several other conditions may occur with 22q11.2 deletion syndrome:

  • Hearing impairment
  • Vision problems
  • Kidney dysfunction
  • Growth delays
  • Feeding difficulties in infants

Prevention

Genetic testing and counseling can be helpful if you have concerns about a family history of 22q11.2 deletion syndrome. Parents with this condition may pass it to their children.

If you’re worried or already have a child with this syndrome, consider seeing a geneticist. These specialized doctors understand genetic conditions and can provide valuable guidance.

A genetic counselor can also help you plan for future pregnancies. They can explain the risks and options available to you.

Early planning and professional advice may help families make informed decisions about having more children.


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Health Writer

Janis's areas of expertise include nutrition, exercise, stress management, and mental health. She is passionate about educating and empowering people to take control of their health and make positive changes that can last a lifetime. Janis believes that small, sustainable changes are the key to long-term success, and she works with her clients to develop personalized plans that fit their individual needs and lifestyles.