An Increased Incidence of Total Anomalous Pulmonary Venous Connection among Hispanics in Southern Nevada

Opitz GBBB syndrome with total anomalous pulmonary venous connection: A new MID1 gene variant

BACKGROUND

Opitz GBBB syndrome (GBBB) is an X-linked disease characterized by midline defects, including congenital heart defects. We present our diagnostic approach to the identification of GBBB in a consanguineous family in which two males siblings were concordant for a total anomalous connection of pulmonary veins and minor facial dysmorphias.

METHODS

Targeted exome sequencing analysis of a 380-gene panel associated with cardiovascular disease was performed on the propositus. Interpretative analysis of the exome results was conducted, and 3D models of the protein changes were generated.

RESULTS

We identified a NM_000381.4:c.608G>A;p.(Arg203Gln) change in MID1, affecting the conformation of the B-box 2 domain of the protein, with a zinc finger structure and associated protein interactions. This clinical phenotype is consistent with GBBB; however, the type of congenital heart disease observed in this case has not been previously reported.

CONCLUSION

A new likely pathogenic variant on MID1 c.608G>A was found to be associated with Opitz GBBB syndrome.

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.

Detecting Critical Congenital Heart Disease in Nevada

Background:

We reviewed data on patients born with critical congenital heart disease in the state of Nevada and analyzed detection via prenatal diagnosis versus newborn pulse oximetry screening, location of birth, and gestational age at birth.

Methods:

We inquired our databases and electronic health records for all patients with critical congenital heart disease born in Nevada between January 2016 and May 2019.

Results:

We identified 218 live born patients. Of the 218, average gestational age was 38 weeks (±2.2 weeks). Of the 218, 171 (78%) were prenatally diagnosed, 37 (17%) were diagnosed by immediate postnatal signs and symptoms, 8 (4%) had false-negative pulse oximetry screens that resulted in post-hospital discharge presentations, and 2 (1%) had positive pulse oximetry screens. The eight post-hospital discharge presentations included four in extremis, two with extreme cyanosis, and two dying at home. Of the 171 prenatally diagnosed patients, 157 (92%) were born at the Nevada hospital with the congenital cardiac unit.

Conclusion:

To the best of our knowledge, our results represent the highest statewide, general population prenatal detection of critical congenital heart disease in the United States. Our high prenatal detection rate led to the majority of patients being born at the Nevada facility with the congenital heart unit, limiting intrastate neonatal transports. On average, patients were born at term. Further, in Nevada, state-mandated, universal pulse oximetry screening resulted in more false-negative results than positive results

Maternal Obesity as a Risk Factor for the Development of Total Anomalous Pulmonary Venous Connection in Their Offspring

The incidence of total anomalous pulmonary venous connection (TAPVC) in the Caucasian population is 2.5/100,000 live births (LB), and the incidence in the Hispanic population is 19.8/100,000 LB. Without knowing the exact etiology for the development of congenital heart disease, our objective was to determine the maternal factors associated with the development of TAPVC.

METHODS

55 mother-child binomials with isolated TAPVC (group I) and 152 healthy mother-child binomials (group II) were included. Both groups had no maternal history of addiction, pre-eclampsia, or type 1, 2 or gestational diabetes mellitus. Complete clinical histories were obtained for the women in both groups and perinatal and birth data were recorded. In addition, genealogies across three generations were constructed to determine affected first- or second-degree relatives with complex congenital heart disease.

RESULTS

Among the maternal characteristics analyzed, women in group I had a higher number of pregnancies before gestation of the index case (p = <0.05), and the Body Mass Index (BMI) before pregnancy was higher compared to Group II (p < 0.05), with an adjusted risk of OR = 3.6 (p = 0.011). The family history showed a higher prevalence in the group of patients with TAPVC compared to healthy children (p < 0.05).

CONCLUSION

Maternal obesity before pregnancy is a risk factor for the development of CATVP in children in the Mexican population.