Genetic Test, Risk Prediction, and Counseling

Diagnostic application of exome sequencing in Chinese children with suspected inherited kidney diseases

Background: Inherited kidney diseases (IKDs) are a group of kidney diseases characterized by abnormal kidney structure or function caused by genetic factors, but they are not easily diagnosed in childhood due to either nonspecific symptoms and signs or clinically silent symptoms in the early stages until the progressive stages, even end-stages. Early diagnosis of IKDs is very urgent for timely treatment and improving outcomes of patients. So far, the etiological diagnosis has been accelerated with the advance of clinical genetic technology, particularly the advent of next-generation sequencing (NGS) that is not only a powerful tool for prompt and accurate diagnosis of IKDs but also gives therapy guidance to decrease the risk of unnecessary and harmful interventions. Methods: The patients presenting with urinalysis abnormalities or structural abnormalities from 149 Chinese families were enrolled in this study. The clinical features of the patients were collected, and the potentially causative gene variants were detected using exome sequencing. The clinical diagnostic utility of the genetic testing was assessed after more detailed clinical data were analyzed. Result: In total, 55 patients identified having causative variants by exome sequencing were genetically diagnosed, encompassing 16 (29.1%) autosomal dominant IKDs, 16 (29.1%) autosomal recessive IKDs, and 23 (41.8%) X-linked IKDs, with 25 unreported and 45 reported variants. The diagnostic yield was 36.9%. The utility of the exome sequencing was accessed, 12 patients (21.8%) were confirmed to have suspected IKDs, 26 patients (47.3%) discerned the specific sub-types of clinical category, and 17 patients (30.9%) with unknown etiology or lack of typical manifestations were reclassified. Conclusion: Our study supported that genetic testing plays a crucial role in the early diagnosis for children with IKDs, which affected follow-up treatment and prognostic assessment in clinical practice. Moreover, the variant spectrum associated with IKDs was expanded.

Knowledge and perceptions of the genetic counseling profession among a national cross-sectional sample of U.S. adults

Awareness of the genetic counseling (GC) profession may influence access to genetic services, yet awareness among the U.S. population is unknown. A survey of U.S. adults was conducted using age- and sex-based quotas. Participants were asked if they had heard of the GC profession and to describe what genetic counselors (GCs) do. After reading a brief description of what GCs do, participants were asked the likelihood they would request to see a genetic counselor if they were concerned about a genetic condition. We used descriptive statistics to characterize the population, logistic regression to determine factors related to awareness of the GC profession, and ordinary least squares regression to identify which factors correlated with likelihood of seeking GC services. Thematic analysis was used to code open-ended responses. Among the final sample of 543, the majority were White individuals (79.7%) with an average age of 46.5 and median income between $60,000 and $69,999. Although 20% indicated they had heard of the GC profession, further analysis of the qualitative follow-up question suggested only 13.4% understood the role of GCs (CI 10.6%-16.3%). Factors positively and significantly correlated with knowledge of the GC profession included identifying as White or female and having higher educational attainment or higher science knowledge after controlling for income, age, and political views. Approximately 45% of respondents indicated they would likely or very likely seek GC if concerned about a genetic condition. Biological sex, age, religious affiliation, science knowledge, and awareness of the GC profession were significantly correlated with likelihood of seeking GC services while controlling for race, income, educational attainment, and political views. Curiosity/interest, the perception of benefits, and trust in GCs were all major themes that emerged to explain reasons for seeking an appointment with GCs. Lack of awareness, lack of perceived benefit, and lack of trust in GCs or greater trust in other healthcare providers were reasons for not wanting a GC appointment. Despite the 50-year existence of the GC profession, awareness remains low and negative attitudes exist.

Disease-modifying genetic factors in cystic fibrosis

PURPOSE OF REVIEW

To compile data from the past 10 years regarding the role of modifying genes in cystic fibrosis (CF).

RECENT FINDINGS

CF is a model disease for understanding of the action of modifying genes. Although it is a monogenic (CFTR) autosomal recessive disease, CF presents with wide phenotypic variability. In CF, variability occurs with different intensity among patients by each organ, being organ-specific, resulting from the mutual interaction of environmental and genetic factors, including CFTR mutations and various other genes, most of which are associated with inflammatory processes. In individuals, using precision medicine, gene modification studies have revealed individualized responses to drugs depending on particular CFTR mutations and modifying genes, most of which are alternative ion channels.

SUMMARY

Studies of modifying genes in CF allow: understanding of clinical variability among patients with the same CFTR genotype; evaluation of precision medicine; understanding of environmental and genetic effects at the organ level; understanding the involvement of genetic variants in inflammatory responses; improvements in genetic counseling; understanding the involvement of genetic variants in inflammatory responses in lung diseases, such as asthma; and understanding the individuality of the person with the disease.