22q11.2 deletion syndrome and congenital heart disease

22q11.2 deletion syndrome and congenital heart disease. 22q11.2 deletion syndrome is the most common microdeletion syndrome with a variable range of clinical features, including cardiac abnormalities. This paper examines the prevalence, identification, outcomes, and clinical management of congenital heart defects (CHD) in patients with 22q11.2 deletion syndrome.

chromosome 22

The prevalence of CHD in 22q11.2 deletion syndrome is highly variable and not clearly defined. The reported number of patients with the 22q11.2 deletion and CHD may vary due to age of diagnosis, and setting in which the diagnosis is made. A hospital-based study reported that 75-80% of patients with 22q11.2 deletion syndrome had CHD. Even in outpatient, non-cardiac settings, the prevalence of CHD is at least 50%. Prevalence strongly depends on patients’ age: in one clinic CHD were found in 63% of neonates with del 22q11.2, but only in 30% of children above 3 years old.

The spectrum of CHD in 22q11.2 deletion syndrome is very wide, but conotruncal defects (tetralogy of Fallot [TOF], interrupted aortic arch type B [IAA-B] and truncus arteriosus) are especially common. More than 50% of all patients with IAA-B and up to 35% of all patients with truncus arteriosus and TOF have del 22q11.2. It is desirable to perform a cytogenetic examination in all patients with these types of CHD to exclude del 22q11.2 even if the patient does not have other typical manifestations of the syndrome. Early diagnosis allows for timely evaluations, anticipatory care, counseling, and the ability to address age-specific complications associated with the deletion.

When compared to their non-syndromic counterparts CHD patients with the 22q11.2 deletion experience comparable to higher rates of mortality, and increased peri-operative morbidity. Specifics of the post-operative complications vary, but center around cardiopulmonary complications, increased intensive care, and longer hospital stays.

The review highlights the significance of screening and diagnosis of 22q11.2 deletion syndrome in patients with congenital heart disease, describing the most common cardiac presentations and potential morbidity and mortality associated with the syndrome.

Goldmuntz E. 22q11.2 deletion syndrome and congenital heart disease. Am J Med Genet Part C. 2020, v. 184, 64-72.

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