Familial scimitar syndrome: three-dimensional visualization of anomalous pulmonary vein in young sisters

The frequency and efficacy of genetic testing in individuals with scimitar syndrome

BACKGROUND

Scimitar syndrome is a rare CHD composed of partial anomalous pulmonary venous connection from the right lung, via a scimitar vein, to the inferior vena cava rather than the left atrium. Genetic conditions associated with scimitar syndrome have not been well investigated at present.

METHODS

Our study included patients with scimitar syndrome diagnosed at Texas Children's Hospital from January 1987 to July 2020. Medical records were evaluated to determine if genetic testing was performed, including chromosomal microarray analysis or whole-exome sequencing. Copy number variants identified as pathogenic/likely pathogenic and variants of unknown significance were collected. Analyses of cardiac and extracardiac findings were performed via chart review.

RESULTS

Ninety-eight patients were identified with scimitar syndrome, 89 of which met inclusion criteria. A chromosome analysis or chromosomal microarray analysis was performed in 18 patients (20%). Whole-exome sequencing was performed in six patients following negative chromosomal microarray analysis testing. A molecular genetic diagnosis was made in 7 of 18 cases (39% of those tested). Ninety-six per cent of the cohort had some type of extracardiac finding, with 43% having asthma and 20% having a gastrointestinal pathology. Of the seven patients with positive genetic testing, all had extracardiac anomalies with all but one having gastrointestinal findings and 30% having congenital diaphragmatic hernia.

CONCLUSIONS

Genetic testing revealed an underlying diagnosis in roughly 40% of those tested. Given the relatively high prevalence of pathogenic variants, we recommend chromosomal microarray analysis and whole-exome sequencing for patients with scimitar syndrome and extracardiac defects.

Isolated partial right lower lobe pulmonary venous drainage into the right atrium as a cause of pulmonary hypertension in a middle-aged woman

Partial anomalous pulmonary venous connection is a rare congenital disease characterized by drainage of one or several pulmonary veins into the systemic venous system. It is extremely rare as an isolated anomaly. We report the case of a middle-aged woman with isolated drainage of an enormously enlarged right lower pulmonary vein into the right atrium with significant left-to-right shunt, severe right ventricular enlargement, and pulmonary hypertension.

Uncommon variants of the scimitar syndrome in two siblings

The Scimitar syndrome is a complex association of cardiovascular and bronchopulmonary abnormalities, with the main feature a partial or total anomalous right pulmonary venous drainage to the inferior vena cava. A number of cases that lack of all the features of the typical syndrome have been described as Scimitar variant, but the incidence is rare. Familial occurrence is exceptional and limited to few cases in literature. We report two sibling diagnosed with an uncommon variant of the Scimitar syndrome.

A familial variant of the Scimitar syndrome with a meandering pulmonary vein

We report a rare variant of the Scimitar syndrome, in which the right lower pulmonary vein takes a meandering course before finally connecting in normal fashion to the left atrium. The pulmonary parenchymal segment drained by the tortuous vein is supplied by a systemic collateral artery, which was coiled via a catheter. We also closed the intracardiac defects by surgery. The elder brother of the patient had classical Scimitar syndrome.

Scimitar vein anomaly with multiple cardiac malformations, craniofacial, and central nervous system abnormalities in a brother and sister: familial scimitar anomaly or new syndrome?

The scimitar vein "syndrome" is an anomaly of lobar aplasia or hypoplasia and total or partial anomalous venous drainage of one lung. We report a brother and sister born to nonconsanguineous Italian parents with a fatal infantile form of scimitar vein anomaly associated to multiple cardiac anomalies. The infants had major craniofacial anomalies. In addition, the boy had iris coloboma and enlarged cisterna magna; both sibs showed poor brain myelination at neuroimaging confirmed by histopathology in the girl. The cardiovascular system in the family members was fully investigated and all results were completely normal. The association of the above craniofacial anomalies has been occasionally mentioned in syndromes with anomalous venous return. The familial occurrence of isolated total anomalous pulmonary venous return has been documented in sibs, first cousins, and through consecutive generations. Familial pulmonary hypoplasia, as an isolated finding, has been observed in siblings and twins. To the best of our knowledge, even though five familial cases of scimitar "syndrome" have been described thus far, the constellation of anomalies shown by these two sibs has not been reported previously. It appears that scimitar vein "syndrome" is not a "syndrome" per se: it is most likely an anomaly of heterogeneous etiology. This family may represent its own novel syndrome of multiple congenital anomalies of which scimitar vein is a component.