Summary of genetic findings in 42 out of 230 patients with tetralogy of Fallot
| n | % | Gene/locus | Mutation/aberration | Phenotype |
| 17 | 7.4 | 22q11.2 | Common 3 Mb microdeletion (16x) Proximally nested 1.5 Mb deletion (1) | DiGeorge/VCFS spectrum |
| 12 | 5.2 | Trisomy 21 | 47,XY,t(4;21)(q12;q11.2),+21 46,XX,der (15;21)(p10;p10)+21 47,XX/XY,+21 (7x) 47,XY,+21 in female patient* 100 K SNP array enh(21) (1x) | Down syndrome; Down syndrome and Swyer syndrome*: AVSD, hypoplastic right ventricle, right aortic arch, external and internal genitalia (uterus) female, frequent infections |
| 3 | 1.3 | Chromosomal aberrations other than trisomy 21 | der(19)(pter::p13.2-13.3::13.3-qter) de novo | Height/weight <P3, mental retardation, impaired hearing, frequent infections, craniofacial dysmorphy, restrictive VSD, LAA, aberrant subclavian artery |
| del(21)(q22.3) de novo | Height/weight <P3, mental retardation, cleft palate, inguinal hernias, hip dysplasia, LSVC, perimembranous VSD, additional VSD, juxtaductal coarctation, LAA, aberrant subclavian artery | |||
| 47,XXX | height/weight >P97, scoliosis, frequent infections, long, spherical infundibulum, juxtaductal coarctation | |||
| 4/19 tested | 1.7 | Microaberrations other than 22q11.2 deletion | del(1)(p32.2p31.1), 14 Mb, parents not available | Mental retardation, height/length <P3, agenesis of corpus callosum, hydrocephalus, seizures, renal dysplasia, jejunal atresia, clubfoot, coronary arteries abnormal, LCA from RCA, RAA, right vertebral arteria from aortic arch |
| del(6)(q16.1q21), 12.80 Mb, de novo | Mental retardation, behavioral problems, thymic aplasia, frequent infections, DORV | |||
| del(7)(p22.3p22.2), 1.50 Mb, de novo | Mental retardation, cleft palate, facial dysmorphism, scoliosis, DORV, RAA | |||
| del(19)(p13.11p12), 4.5 Mb and dup(19)(q13.1), 2.70 Mb, both de novo | mental retardation, craniofacial anomalies, coronary artery anomalies (LAD from RCA) | |||
| 3 | 1.3 | JAG1 | c.2810G→A (p.R937Q) | Alagille facies, mild mental retardation, RAA, singular origin of left subclavian artery, truncus bicaroticus |
| c.439C→T (p.Q147X), parents not available | Alagille facies, severe mental retardation, hypernasality, dysplastic ears, flat nasal bridge, wide-set nipples, extrahepatic biliary atresia, peripheral pulmonary stenosis | |||
| c.2508_2509insTG (p.D837WfsX870) | Alagille facies, premature birth, microcephaly, dystrophy, severe mental retardation, extrahepatic biliary atresia (liver transplantation at 2 years of age), juxtaductal coarctation, peripheral pulmonary stenosis, truncus bicaroticus | |||
| 2 | 0.9 | NKX2.5 | R25C | Dextroposition of the aorta >50% from right ventricle, aberrant subclavian artery |
| R25C and 46,XY,inv(5)(p14.2q13.1) | Normal facies, no mental retardation, elongated infundibulum, LAA | |||
| 1 | 0.4 | TBX1 | c.1399–1428dup30, excluded in mother, father not available | Scoliosis, facial asymmetry, upslanting palpebral fissures, absent PV, isolated left pulmonary artery |
↵* In a female one would expect an XX karyotype; to clarify that this patient in addition to trisomy 21 (Down syndrome) also has a disorder of sexual development, which is named ‘Swyer syndrome’.
AVSD, atrioventricular septal defect; DORV, double outlet right ventricle; LAA, left aortic arch; LAD, left anterior descending coronary artery; LSVC, left superior vena cava; PV, pulmonary vein; RAA, right aortic arch; RCA, right coronary artery; ToF, tetralogy of Fallot; VCFS, velocardiofacial syndrome; VSD, ventricular septal defect.