Nursing Care of Infants and Children With Congenital Heart Disease and Associated Genetic Conditions

Lauren T. Cobert

Disclosures

Pediatr Nurs. 2019;45(2):75-85. 

In This Article

22q11.2 Deletion Syndrome

Etiology/Genetics

22q11.2 deletion syndrome (22q11.2DS) is also known by the acronym CATCH, which stands for Cardiac anomalies, Abnormal facies, T cell deficit/Thymic hypoplasia, Cleft palate, and Hypocalcemia (Burn, 1999; Wilson, Burn, Scambler, & Goodship, 1993). It is now recognized that a 22q11.2 deletion is the cause of several syndromes, including DiGeorge syndrome (de la Chapelle, Herva, Koivisto, & Aula, 1981; DiGeorge, 1965), cardiofacial syndrome (Cayler, 1969; Giannotti, Digilio, Marino, Mingarelli, & Dallapiccola, 1994), conotruncal anomaly face syndrome (Takao syndrome) (Burn et al., 1993; Kinouchi, Mori, Ando, & Takao, 1976; Matsuoka et al., 1994; Takao, Ando, Cho, Kinouchi, & Murakami, 1980), velocardiofacial syndrome (Shprintzen syndrome) (Driscoll et al., 1993; Shprintzen et al., 1978), and cases of autosomal dominant Opitz G/BBB syndrome (McDonald-McGinn et al., 1995; Opitz, Frías, Gutenberger, & Pellet, 1969; Opitz, Summitt, & Smith, 1969). Estimated incidence of 22q11. 2DS is 1 in 4,000 live births, making it second only to trisomy 21 as the leading cause of developmental delay and major CHD (Bassett et al., 2011).

Most congenital abnormalities associated with 22q11.2DS can be attributed to an embryologic disruption in the development of the pharyngeal arches, which give rise to the thymus, parathyroid glands, aortic arch, and craniofacial structures. The majority of 22q11.2 deletion syndrome cases are caused by de novo deletions, but it has an autosomal dominant pattern of inheritance in 6% to 28% of cases, highlighting the importance of genetic counseling for future pregnancies (Chen, 2017; Fahed et al., 2013).

Clinical Features

Eighty-five percent of patients with 22q11.2DS present with cardiac defects (Jones et al., 2013). The most common defects are tetralogy of Fallot, truncus arteriosus, interrupted aortic arch type B, ventricular septal defects, and aortic arch anomalies (OMIM, n.d.). Characteristic facies include almond shaped eyes, prominent nose, bulbous nasal tip, small alar base, malar flatness, and asymmetric crying facies (Habel et al., 2014). T cell deficiency is due to thymic hypoplasia or aplasia and affects up to 75% of children with 22q11.2DS (Chen, 2017). Cleft palate and velopharyngeal incompetence may be repaired surgically usually around 1 year of age, and endotracheal intubation or tracheotomy may be indicated in some cases (Swillen & McDonald-McGinn, 2015). Hypocalcemia due to hypo parathyroidism is most prominent during the neonatal period (Swillen & McDonald-McGinn, 2015). Between one-third to one-half of children with 22q11.2DS will suffer from neurodevelopmental delay, learning difficulties, and psychiatric disorders, such as ADHD, ASD, anxiety disorders, mood disorders, and psychotic disorders (Bassett, Costain, & Marshall, 2017; Jonas, Montojo, & Bearden, 2014; Wenger et al., 2016). Schizophrenia commonly manifests in adolescence and adulthood (Bassett et al., 2017; Baughman, Morris, Jensen, & Austin, 2015). About one-third of 22q11.2DS patients will have genitourinary abnormalities, such as renal agenesis, dysplastic or cystic kidneys, hydro nephrosis, cryptorchidism, hypospadias, or inguinal hernia (McDonald-McGinn et al., 2015).

Recognition of 22q11.2DS can be difficult due to the wide variability of phenotypic expression. Some children may only present with subtle abnormalities without major cardiac malformations. Physical assessment and identification of the hallmark problems, which include conotruncal cardiac defects, immunodeficiency/chronic infections, palatal abnormalities, feeding and swallowing issues, developmental and/or learning disabilities, and behavioral problems, can assist with diagnosis (Bassett et al., 2011). Red flags in neonates and infants include nasal regurgitation with feeding, hypernasal crying, tetany and seizures, recurrent otitis media and upper respiratory infections, delayed infantile milestones, and poor growth (Bassett et al., 2011). Children and adolescents may present with characteristic facial features, autoimmune diseases, speech and learning delays, psychiatric illnesses, short stature, and thyroid disease (Bassett et al., 2011; Friedman, Rienstein, Yeshayahu, Gothelf, & Somech, 2016).

Diagnosis

Diagnosis may be suspected prenatally by single-nucleotide polymorphism-based non-invasive prenatal testing (Gross et al., 2016). Currently 10 U.S. states include severe combined immunodeficiency (SCID) testing in their newborn screening programs, which can identify infants with T cell lymphopenia (Barry et al., 2017; CDC, 2018b). The diagnosis can be confirmed by CMA. Fluorescence in situ hybridization (FISH) has become a less popular testing method due to lower sensitivity and higher cost compared to CMA (Crotwell & Hoyme, 2012; Geddes, Butterly, & Sajan, 2015).

Other investigatory tests include complete blood cell count with differential, immunoglobulin levels, lymphocyte phenotyping, flow cytometry analysis of T cells, autoantibody testing, serum calcium level, thyroid function tests, renal ultrasound, vision and hearing examinations, chest X-ray, echocardiogram, and brain MRI (Chen, 2017).

Management

A multidisciplinary approach to the management of 22q11.2DS includes specialists in genetics, cardiology, gastroenterology, allergy, immunology, plastic surgery, endocrinology, otolaryngology, audiology, SLT, OT, PT, psychology, and psychiatry. Vigilant monitoring and treatment of hypocalcemia and vitamin D supplementation are needed, especially in the neonatal period and during times of biologic stress (i.e., childbirth, acute illness, postoperatively). Some 22q11.2DS patients will have true thymus aplasia and absence of T cells, or complete DiGeorge syndrome, and may require irradiated blood for blood transfusions to avoid graft-versus-host disease, avoidance of live vaccines, antipneumocystis and antifungal prophylaxis, respiratory syncytial virus prophylaxis, immunoglobulin treatment, and thymic or peripheral blood T cell transplantation (Allen, 2012; Hofstetter et al., 2014; Maggadottir & Sullivan, 2013). Young children may struggle with motor, speech, and expressive language delays, necessitating the need for early intervention with speech-language, occupational, and physical therapies (Habel et al., 2014). All children with 22q11.2DS should have an educational evaluation for an IEP. It is recommended that all patients with 22q11.2DS undergo psychological evaluation at an early age with continued surveillance throughout their lifetimes (Fung et al., 2015; Swillen & McDonald-McGinn, 2015; Wenger et al., 2016).

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