High Clinical Exome Sequencing Diagnostic Rates and Novel Phenotypic Expansions for Nonisolated Microphthalmia, Anophthalmia, and Coloboma

Purpose

A molecular diagnosis is only made in a subset of individuals with nonisolated microphthalmia, anophthalmia, and coloboma (MAC). This may be due to underutilization of clinical (whole) exome sequencing (cES) and an incomplete understanding of the genes that cause MAC. The purpose of this study is to determine the efficacy of cES in cases of nonisolated MAC and to identify new MAC phenotypic expansions.

Methods

We determined the efficacy of cES in 189 individuals with nonisolated MAC. We then used cES data, a validated machine learning algorithm, and previously published expression data, case reports, and animal models to determine which candidate genes were most likely to contribute to the development of MAC.

Results

We found the efficacy of cES in nonisolated MAC to be between 32.3% (61/189) and 48.1% (91/189). Most genes affected in our cohort were not among genes currently screened in clinically available ophthalmologic gene panels. A subset of the genes implicated in our cohort had not been clearly associated with MAC. Our analyses revealed sufficient evidence to support low-penetrance MAC phenotypic expansions involving nine of these human disease genes.

Conclusions

We conclude that cES is an effective means of identifying a molecular diagnosis in individuals with nonisolated MAC and may identify putatively damaging variants that would be missed if only a clinically available ophthalmologic gene panel was obtained. Our data also suggest that deleterious variants in BRCA2, BRIP1, KAT6A, KAT6B, NSF, RAC1, SMARCA4, SMC1A, and TUBA1A can contribute to the development of MAC.

Texas H.B. 810: Increased Access to Stem Cell Interventions or an Increase in Unproven Treatments?

Born of the expectations and hype associated with regenerative medicine, there are now numerous clinics around the world selling stem cell-based interventions (SCBI) that have yet to be proven effective or safe, with little to no accounting of the outcomes being collected. In the United States, SCBI are overseen by the U.S. Food and Drug Administration (FDA), but several SCBI clinics have been pushing for policies to expand access and circumvent FDA oversight. Related to this effort, in 2017, Texas passed a bill, HB 810, which allows clinics to provide "investigational stem cell treatments to patients with certain severe chronic diseases or terminal illnesses." In this article, we describe how the new law relates to another deregulation movement, state and federal, the Right to Try laws, the content of HB 810, and the state legislators' intent in passing HB 810.