National Society of Genetic Counselors Code of Ethics: Explication of 2017 Revisions.

The Code of Ethics (COE) of the National Society of Genetic Counselors (NSGC) was adopted in 1992 and was later revised and adopted in 2006. In 2016, the NSGC Code of Ethics Review Task Force (COERTF) was convened to review the COE. The COERTF reviewed ethical codes written by other professional organizations and suggested changes that would better reflect the current and evolving nature of the genetic counseling profession. The COERTF received input from the society's legal counsel, Board of Directors, and members-at-large. A revised COE was proposed to the membership and approved and adopted in April 2017. The revisions and rationale for each are presented.

Social comparisons and quality of life following a prostate cancer diagnosis.

PURPOSE: The objective was to explore the relationships among cognitive appraisals of prostate cancer (challenge, threat, and harm/loss), social comparisons, and quality of life in men previously diagnosed. Design, Sample, & Methods: Men who had participated in prostate cancer support groups completed a cross-sectional questionnaire (N = 189). Multivariable linear regression was used to evaluate social comparisons as mediators of quality of life while controlling for uncertainty and optimism. FINDINGS: Positive and negative social comparisons were parallel mediators of the relationships between challenge or threat appraisals and quality of life, while only negative social comparisons mediated the relationship between harm/loss appraisals and quality of life. CONCLUSIONS: These findings demonstrate the importance of social comparisons in accounting for the effect of cognitive appraisals of prostate cancer on quality of life among men in support groups. Implications for Psychosocial Providers: Interventions to improve quality of life could address reduction of maladaptive comparisons, a strategy that could be tailored based on the patient's appraisal of prostate cancer.

Effects of undergoing multiplex genetic susceptibility testing on parent attitudes towards testing their children.

BACKGROUND: Parents may pursue common disease risk information about themselves via multiplex genetic susceptibility testing (MGST) for their children. PURPOSE: To prospectively assess whether parents who received MGST disclosed their test results to their child, intended to change the child's health habits, or have the child tested. METHODS: Eighty parents who opted for free MGST completed an online survey about a child in their household before undergoing MGST and a follow-up telephone survey 3 months after receiving results. RESULTS: Few parents (21 %) disclosed results to the child. Undergoing MGST was unrelated to intentions to change the child's health habits but did increase parental willingness to test the child. Greater willingness to test a child was associated with positive attitudes toward pediatric genetic testing and intentions to change the child's health habits. CONCLUSION: The experience of receiving MGST had little impact on parents' perceptions or behaviors related to their minor child.

The National Institutes of Health Undiagnosed Diseases Program: insights into rare diseases.

PURPOSE: This report describes the National Institutes of Health Undiagnosed Diseases Program, details the Program's application of genomic technology to establish diagnoses, and details the Program's success rate during its first 2 years. METHODS: Each accepted study participant was extensively phenotyped. A subset of participants and selected family members (29 patients and 78 unaffected family members) was subjected to an integrated set of genomic analyses including high-density single-nucleotide polymorphism arrays and whole exome or genome analysis. RESULTS: Of 1,191 medical records reviewed, 326 patients were accepted and 160 were admitted directly to the National Institutes of Health Clinical Center on the Undiagnosed Diseases Program service. Of those, 47% were children, 55% were females, and 53% had neurologic disorders. Diagnoses were reached on 39 participants (24%) on clinical, biochemical, pathologic, or molecular grounds; 21 diagnoses involved rare or ultra-rare diseases. Three disorders were diagnosed based on single-nucleotide polymorphism array analysis and three others using whole exome sequencing and filtering of variants. Two new disorders were discovered. Analysis of the single-nucleotide polymorphism array study cohort revealed that large stretches of homozygosity were more common in affected participants relative to controls. CONCLUSION: The National Institutes of Health Undiagnosed Diseases Program addresses an unmet need, i.e., the diagnosis of patients with complex, multisystem disorders. It may serve as a model for the clinical application of emerging genomic technologies and is providing insights into the characteristics of diseases that remain undiagnosed after extensive clinical workup.

Factors associated with perceived uncertainty among parents of children with undiagnosed medical conditions.

Uncertainty is a pervasive characteristic of illness. Yet little is known about the individual or situational factors that contribute to perceptions of uncertainty. The present study aims to examine the factors that contribute to perceived uncertainty among parents of a child with an undiagnosed condition. Two hundred sixty-six parents of a child, or children, affected by an undiagnosed medical condition for at least 2 years completed an electronically administered mixed-methods survey assessing theoretical predictors of perceived uncertainty. Multivariate linear regression analyses were used to identify the relationship of key variables to perceived uncertainty. Parents' perceived control and optimism were negatively associated with uncertainty (B=-4.044, P≤0.001, B=-0.477, P≤0.05). Subjective disease severity was positively associated with perceived uncertainty (B=1.797, P≤0.05). Our findings suggest that parents who experience greater uncertainty feel less control over their child's medical condition, which may lead to less effective coping and poorer adaptation. Parents who are less optimistic or who perceive their child's disease as more severe may benefit most from interventions that target situations where parents perceive the least control, thereby enhancing coping and ultimately, adaptation.

Allelic hierarchy of CDH23 mutations causing non-syndromic deafness DFNB12 or Usher syndrome USH1D in compound heterozygotes.

BACKGROUND: Recessive mutant alleles of MYO7A, USH1C, CDH23, and PCDH15 cause non-syndromic deafness or type 1 Usher syndrome (USH1) characterised by deafness, vestibular areflexia, and vision loss due to retinitis pigmentosa. For CDH23, encoding cadherin 23, non-syndromic DFNB12 deafness is associated primarily with missense mutations hypothesised to have residual function. In contrast, homozygous nonsense, frame shift, splice site, and some missense mutations of CDH23, all of which are presumably functional null alleles, cause USH1D. The phenotype of a CDH23 compound heterozygote for a DFNB12 allele in trans configuration to an USH1D allele is not known and cannot be predicted from current understanding of cadherin 23 function in the retina and vestibular labyrinth. METHODS AND RESULTS: To address this issue, this study sought CDH23 compound heterozygotes by sequencing this gene in USH1 probands, and families segregating USH1D or DFNB12. Five non-syndromic deaf individuals were identified with normal retinal and vestibular phenotypes that segregate compound heterozygous mutations of CDH23, where one mutation is a known or predicted USH1 allele. CONCLUSIONS: One DFNB12 allele in trans configuration to an USH1D allele of CDH23 preserves vision and balance in deaf individuals, indicating that the DFNB12 allele is phenotypically dominant to an USH1D allele. This finding has implications for genetic counselling and the development of therapies for retinitis pigmentosa in Usher syndrome. ACCESSION NUMBERS: The cDNA and protein Genbank accession numbers for CDH23 and cadherin 23 used in this paper are AY010111.2 and AAG27034.2, respectively.

The relationship between the genetic counseling profession and the disability community: a commentary.

Since the inception of the field of genetic counseling, the profession has had a tenuous relationship with the disability community. Genetic counselors both offer prenatal diagnostic testing that allows individuals the opportunity to avoid the birth of a child with a disability and they advocate for the rights of individuals who have a disability. Some in the disability rights community have argued that they feel their lives and the lives of the disabled individuals in their families judged by the offer of prenatal genetic diagnosis and by the attitudes of genetic service providers they encounter in clinical settings. Select voices from the disability community fear that the result of developing technologies may contribute to a world less tolerant of disabilities. The available empirical data suggest that genetic counselors do little to counteract these perspectives. Although limited, investigations into the attitudes and practices of genetic counselors suggest that they have a more negative perspective on disabilities than individuals whose lives are directly affected by them and these attitudes may affect their description of disabling conditions in a prenatal setting. The National Society of Genetic Counselors, the organization that represents the profession in the US has more publicly aligned itself with abortion service providers over disease advocacy organizations, thus subjecting itself to the perception of bias. We suggest possible solutions to these criticisms and argue that individually and collectively, genetic counseling professionals should develop and identify opportunities to more fully support and advocate for the needs of a broader spectrum of clients.

Hypo-functional SLC26A4 variants associated with nonsyndromic hearing loss and enlargement of the vestibular aqueduct: genotype-phenotype correlation or coincidental polymorphisms?

Hearing loss with enlargement of the vestibular aqueduct (EVA) can be associated with mutations of the SLC26A4 gene encoding pendrin, a transmembrane Cl(-)/I(-)/HCO(3)(-) exchanger. Pendrin's critical transport substrates are thought to be I(-) in the thyroid gland and HCO(3)(-) in the inner ear. We previously reported that bi-allelic SLC26A4 mutations are associated with Pendred syndromic EVA whereas one or zero mutant alleles are associated with nonsyndromic EVA. One study proposed a correlation of nonsyndromic EVA with SLC26A4 alleles encoding pendrin with residual transport activity. Here we describe the phenotypes and SLC26A4 genotypes of 47 EVA patients ascertained since our first report of 39 patients. We sought to determine the pathogenic potential of each variant in our full cohort of 86 patients. We evaluated the trafficking of 11 missense pendrin products expressed in COS-7 cells. Products that targeted to the plasma membrane were expressed in Xenopus oocytes for measurement of anion exchange activity. p.F335L, p.C565Y, p.L597S, p.M775T, and p.R776C had Cl(-)/I(-) and Cl(-)/HCO(3)(-) exchange rate constants that ranged from 13 to 93% of wild type values. p.F335L, p.L597S, p.M775T and p.R776C are typically found as mono-allelic variants in nonsyndromic EVA. The high normal control carrier rate for p.L597S indicates it is a coincidentally detected nonpathogenic variant in this context. We observed moderate differential effects of hypo-functional variants upon exchange of HCO(3)(-) versus I(-) but their magnitude does not support a causal association with nonsyndromic EVA. However, these alleles could be pathogenic in trans configuration with a mutant allele in Pendred syndrome.

Modification of human hearing loss by plasma-membrane calcium pump PMCA2.

Five adult siblings presented with autosomal recessive sensorineural hearing loss: two had high-frequency loss, whereas the other three had severe-to-profound loss affecting all frequencies. Genetic evaluation revealed that a homozygous mutation in CDH23 (which encodes cadherin 23) caused the hearing loss in all five siblings and that a heterozygous, hypofunctional variant (V586M) in plasma-membrane calcium pump PMCA2, which is encoded by ATP2B2, was associated with increased loss in the three severely affected siblings. V586M was detected in two unrelated persons with increased sensorineural hearing loss, in the other caused by a mutation in MYO6 (which encodes myosin VI) in one and by noise exposure, suggesting that this variant may modify the severity of sensorineural hearing loss caused by a variety of factors.

Investigation of the role of congenital cytomegalovirus infection in the etiology of enlarged vestibular aqueducts.

OBJECTIVE: To determine whether congenital cytomegalovirus (CMV) infection is an etiologic factor in the pathogenesis of enlarged vestibular aqueducts (EVA). DESIGN: Two different cohort studies. Subjects The study population comprised 19 subjects with a history of congenital CMV infection and sensorineural hearing loss (cohort 1); 39 subjects with nonsyndromic EVA and their unaffected mothers (cohort 2); and 16 control subjects with EVA associated with Pendred syndrome and bi-allelic mutations of the SLC26A4 gene and their unaffected mothers. RESULTS: In cohort 1, we detected EVA in 0 of 19 subjects with congenital CMV infection and sensorineural hearing loss. In cohort 2, anti-CMV serologic profiles were consistent with possible congenital CMV infection in 10 (26%) of 39 subjects with nonsyndromic EVA and 6 (38%) of 16 control subjects with Pendred syndrome (P = .52). These seroprevalence rates are similar to those expected in the general population (40%). CONCLUSION: In spite of their auditory phenotypic similarities, congenital CMV infection is not a significant factor in the etiology of EVA.

Use of SLC26A4 mutation testing for unilateral enlargement of the vestibular aqueduct.

IMPORTANCE: Approximately one-half of all subjects with unilateral or bilateral hearing loss with enlargement of the vestibular aqueduct (EVA) will have SLC26A4 gene mutations. The number (0, 1, or 2) of mutant alleles of SLC26A4 detected in an individual subject with EVA is each associated with a distinct combination of diagnostic and prognostic information as well as probability of recurrence of EVA in siblings. OBJECTIVE: To evaluate the results of SLC26A4 mutation testing in subjects with unilateral EVA. (The study objective was formulated before data were collected.) DESIGN: Prospective cross-sectional study of cohort ascertained between 1998 and 2012. SETTING: National Institutes of Health Clinical Center, a federal biomedical research facility. PARTICIPANTS: Twenty-four subjects (10 males, 14 females) with unilateral EVA, defined as a midpoint diameter greater than 1.5 mm, who were referred or self-referred to participate in a study about the clinical and molecular analysis of EVA. Twenty-one (87.5%) of 24 subjects were white. Mean age was 10.3 years (age range, 5-39 years). INTERVENTION: SLC26A4 mutation analysis. MAIN OUTCOMES AND MEASURES: Audiometric results, the presence or absence of EVA, and the number of mutant alleles of SLC26A4. RESULTS: Approximately 8.3% of the subjects with unilateral EVA had 2 mutant SLC26A4 alleles, 16.7% had 1 mutant allele, and 75.0% had 0 mutant alleles. CONCLUSIONS AND RELEVANCE: Unilateral EVA can be associated with all possible SLC26A4 genotype results. The distinct combination of prognoses and recurrence probability associated with each genotype supports the clinical use of testing for SLC26A4 mutations in subjects with unilateral EVA.

SLC26A4 genotype, but not cochlear radiologic structure, is correlated with hearing loss in ears with an enlarged vestibular aqueduct.

OBJECTIVES/HYPOTHESIS: Identify correlations among SLC26A4 genotype, cochlear structural anomalies, and hearing loss associated with enlargement of the vestibular aqueduct (EVA). STUDY DESIGN: Prospective cohort survey, National Institutes of Health, Clinical Center, a federal biomedical research facility. METHODS: Eighty-three individuals, 11 months to 59 years of age, with EVA in at least one ear were studied. Correlations among pure-tone hearing thresholds, number of mutant SLC26A4 alleles, and the presence of cochlear anomalies detected by computed tomography or magnetic resonance imaging were examined. RESULTS: Linear mixed-effects model indicated significantly poorer hearing in ears with EVA in individuals with two mutant alleles of SLC26A4 than in those with EVA and a single mutant allele (P = .012) or no mutant alleles (P = .007) in this gene. There was no detectable relationship between degree of hearing loss and the presence of structural cochlear anomalies. CONCLUSIONS: The number of mutant alleles of SLC26A4, but not the presence of cochlear anomalies, has a significant association with severity of hearing loss in ears with EVA. This information will be useful for prognostic counseling of patients and families with EVA.

Evaluation of the thyroid in patients with hearing loss and enlarged vestibular aqueducts.

OBJECTIVE: To evaluate thyroid structure and function in patients with enlargement of the vestibular aqueduct (EVA) and sensorineural hearing loss. DESIGN: Prospective cohort survey. SETTING: National Institutes of Health Clinical Center, a federal biomedical research facility. PATIENTS: The study population comprised 80 individuals, aged 1.5 to 59 years, ascertained on the basis of EVA and sensorineural hearing loss. MAIN OUTCOME MEASURES: Associations among the number of mutant alleles of SLC26A4; volume and texture of the thyroid; percentage of iodine 123 ((123)I) discharged at 120 minutes after administration of perchlorate in the perchlorate discharge test; and peripheral venous blood levels of thyrotropin, thyroxine, free thyroxine, triiodothyronine, thyroglobulin, antithyroid peroxidase and antithyroglobulin antibodies, and thyroid-binding globulin. RESULTS: Thyroid volume is primarily genotype dependent in pediatric patients but age dependent in older patients. Individuals with 2 mutant SLC26A4 alleles discharged a significantly (P < or = .001) greater percentage of (123)I compared with those with no mutant alleles or 1 mutant allele. Thyroid function, as measured by serologic testing, is not associated with the number of mutant alleles. CONCLUSIONS: Ultrasonography with measurement of gland volume is recommended for initial assessment and follow-up surveillance of the thyroid in patients with EVA. Perchlorate discharge testing is recommended for the diagnostic evaluation of patients with EVA along with goiter, nondiagnostic SLC26A4 genotypes (zero or 1 mutant allele), or both.

Nonsyndromic hearing loss DFNA10 and a novel mutation of EYA4: evidence for correlation of normal cardiac phenotype with truncating mutations of the Eya domain.

Dominant, truncating mutations of eyes absent 4 (EYA4) on chromosome 6q23 can cause either nonsyndromic hearing loss DFNA10 or hearing loss with dilated cardiomyopathy (DCM). It has been proposed that truncations of the C-terminal Eya domain cause DFNA10 whereas upstream truncations of the N-terminal variable region cause hearing loss with DCM. Here we report an extended family co-segregating autosomal dominant, postlingual-onset, progressive, sensorineural hearing loss (SNHL) with a novel frameshift mutation, 1,490insAA, of EYA4. The 1,490insAA allele is predicted to encode a truncated protein with an intact N-terminal variable region, but lacking the entire C-terminal Eya domain. Clinical studies including electrocardiography, echocardiography, and magnetic resonance imaging (MRI) of the heart in nine affected family members revealed no DCM or associated abnormalities and confirmed their nonsyndromic phenotype. These are the first definitive cardiac evaluations of DFNA10 hearing loss to support a correlation of EYA4 mutation position with the presence or absence of DCM. These results will facilitate the counseling of patients with these phenotypes and EYA4 mutations.

Mutation of a transcription factor, TFCP2L3, causes progressive autosomal dominant hearing loss, DFNA28.

We ascertained a large American family with an autosomal dominant form of progressive non-syndromic sensorineural hearing loss. After excluding linkage to known deafness loci, we performed a genome-wide scan and found linkage to marker GAAT1A4 on chromosome 8q22 (LOD=5.12 at theta=0), and this locus was designated DFNA28. Sequencing of six candidate genes in the 1.4 cM linked region identified a frameshift mutation (1609-1610insC) resulting in a premature translation stop codon in exon 14 of the gene TFCP2L3 (transcription factor cellular promoter 2-like 3). TFCP2L3 is a member of a family of transcription factor genes whose archetype is TFCP2, a mammalian homolog of the Drosophila gene grainyhead. Northern blot analyses and in situ hybridization studies show that mouse Tfcp2l3 is expressed in many epithelial tissues, including cells lining the cochlear duct, at embryonic day 18.5 and postnatal day 5.