Right atrial isomerism is characterized by bilateral triangular, morphologically right atrial, appendages, both joining the atrial chamber along a broad front with internal terminal crest.

Autosomal visceral heterotaxy-8 (HTX8) is an autosomal recessive developmental disorder characterized by visceral situs inversus associated with complex congenital heart malformations caused by defects in the normal left-right asymmetric positioning of internal organs (summary by Vetrini et al., 2016). For a discussion of the genetic heterogeneity of visceral heterotaxy, see HTX1 (306955).

Gabriele-de Vries syndrome is characterized by mild-to-profound developmental delay / intellectual disability (DD/ID) in all affected individuals and a wide spectrum of functional and morphologic abnormalities. Intrauterine growth restriction or low birth weight and feeding difficulties are common. Congenital brain, eye, heart, kidney, genital, and/or skeletal system anomalies have also been reported. About half of affected individuals have neurologic manifestations, including hypotonia and gait abnormalities. Behavioral issues can include attention-deficit/hyperactivity disorder, anxiety, autism or autistic behavior, and schizoaffective disorder.

Multiple types of congenital heart defects-7 (CHTD7) is an autosomal dominant disorder with incomplete penetrance characterized mainly by tetralogy of Fallot but also including right-sided aortic arch, absent pulmonary valve, and other cardiac abnormalities (Jin et al., 2017, Reuter et al., 2019).

Diaphragmatic hernia-4 with cardiovascular defects (DIH4) is an autosomal recessive congenital anomaly syndrome characterized by the presence of diaphragmatic hernia or eventration apparent at birth. Affected infants have associated pulmonary hypoplasia and respiratory insufficiency resulting in death in infancy. Most also have variable cardiovascular defects, including aortopulmonary window or conotruncal anomalies. Dysmorphic facial features and mild distal limb anomalies are sometimes observed (Beecroft et al., 2021). For a discussion of genetic heterogeneity of congenital diaphragmatic hernia (CDH), see DIH1 (142340).

Multiple types of congenital heart defects-9 (CHTD9) is characterized by common arterial trunk (truncus arteriosus communis) in most patients, associated with other cardiac defects, including tetralogy of Fallot, interrupted aortic arch, right aortic arch, ventricular hypoplasia, and hypoplastic left heart, as well as other vascular and valvular anomalies (Ta-Shma et al., 2013; Guimier et al., 2023). For a general phenotypic description and discussion of genetic heterogeneity of multiple types of congenital heart defects, see CHTD1 (see 306955).