What is 22q11.2 Deletion Syndrome?

Defining 22q11.2 Deletion Syndrome

22q deletion syndrome has been called by many names, reflecting the constellation of clinical manifestations that have been identified over time. More recently, molecular genetic research has revealed that all of the syndromes listed below have one common link … there is a small amount of genetic material missing, termed a microdeletion, on the short arm (referred to as the q arm) of chromosome 22. Many now simply refer to all of these syndromes as 22q11.2 deletion syndrome:

• DiGeorge Syndrome (DGS)
• Velocardiofacial Syndrome (VCFS)
• Conotruncal Anomaly Face Syndrome
• Autosomal Dominant Opitz G/BBB Syndrome
• Cayler Cardiofacial Syndrome
• Shprintzen Syndrome

The 22q11.2 deletion syndrome occurs in approximately 1 out of every 4,000 live births. In most cases, the 22q deletion occurs de novo (the patient is the first in the family to have this deletion).  In approximately one in 10 families (10%) the deletion is present because one of the parents has the same deletion and passes it on to their baby. As a result, parents of a baby born with 22q11.2 deletion syndrome should have a blood test to determine their chances of having other children with the syndrome.

Signs and Symptoms

There are a variety of physical and behavioral disorders that have been linked to 22q11.2 deletion syndrome. The syndrome has the potential to impact every system in the body and can therefore lead to a wide-range of health issues.  The majority of 22q11.2 deletion syndrome patients have congenital heart defects, most often conotruncal abnormalities (tetralogy of Fallot, interrupted aortic arch, ventricular septal defect (VSD), vascular ring, and  truncus arteriosus) and palatal defects, including submucosal cleft palate and velopharyngeal dysfunction (VPD).   VPD (also referred to as velopharyngeal insufficiency, or VPI) is usually manifest as abnormal nasal air escape and hypernasal speech.  Some of the other common problems associated with 22q11.2 deletion syndrome include:

• Feeding difficulties, including nasal regurgitation of food and fluids, vomiting or “spitting up”, gastroesophageal reflux (GERD)
• Hypocalcemia
• Gastrointestinal problems, including constipation, and GERD
• Immune system disorders, including recurrent ear infections (otitis) and sinusitis, respiratory infections, and autoimmune diseases
• Kidney disorders – approximately 35 percent of these patients may have a missing or malformed kidney.
• ENT problems, including laryngeal webs and external ear anomalies
• Asymmetric crying facies
• Cleft lip and palate
• Orthopedic issues, such as scoliosis, club feet, cervical spine abnormalities, and extra fingers or toes
• Inguinal, umbilical and diaphragmatic hernias
• Growth problems, sometimes associated with growth hormone deficiency
• Developmental delays, including both language and motor skills delays
• Autism
• Obsessive-compulsive disorder (OCD)