De novo nonsense mutations in KAT6A, a lysine acetyl-transferase gene, cause a syndrome including microcephaly and global developmental delay.

Chromatin remodeling through histone acetyltransferase (HAT) and histone deactylase (HDAC) enzymes affects fundamental cellular processes including the cell-cycle, cell differentiation, metabolism, and apoptosis. Nonsense mutations in genes that are involved in histone acetylation and deacetylation result in multiple congenital anomalies with most individuals displaying significant developmental delay, microcephaly and dysmorphism. Here, we report a syndrome caused by de novo heterozygous nonsense mutations in KAT6A (a.k.a., MOZ, MYST3) identified by clinical exome sequencing (CES) in four independent families. The same de novo nonsense mutation (c.3385C>T [p.Arg1129∗]) was observed in three individuals, and the fourth individual had a nearby de novo nonsense mutation (c.3070C>T [p.Arg1024∗]). Neither of these variants was present in 1,815 in-house exomes or in public databases. Common features among all four probands include primary microcephaly, global developmental delay including profound speech delay, and craniofacial dysmorphism, as well as more varied features such as feeding difficulties, cardiac defects, and ocular anomalies. We further demonstrate that KAT6A mutations result in dysregulation of H3K9 and H3K18 acetylation and altered P53 signaling. Through histone and non-histone acetylation, KAT6A affects multiple cellular processes and illustrates the complex role of acetylation in regulating development and disease.

Factors Associated with Uptake of Genetics Services for Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a common cardiovascular disorder with variable expressivity and incomplete penetrance. Clinical guidelines recommend consultation with a genetics professional as part of an initial assessment for HCM, yet there remains an underutilization of genetics services. We conducted a study to assess factors associated with this underutilization within the framework of the Health Belief Model (HBM). An online survey was completed by 306 affected individuals and at risk family members. Thirty-seven percent of individuals (113/306) had visited a genetics professional for reasons related to HCM. Genetic testing was performed on 53 % (162/306). Individuals who had undergone testing were more likely to have seen a genetics professional (p < 0.001), had relatives with an HCM diagnosis (p = 0.002), and have a known familial mutation (p < 0.001). They were also more likely to agree that genetic testing would satisfy their curiosity (p < 0.001), provide reassurance (p < 0.001), aid family members in making healthcare decisions (p < 0.001), and encourage them to engage in a healthier lifestyle (p = 0.002). The HBM components of cues to action and perceived benefits and barriers had the greatest impact on uptake of genetic testing. In order to ensure optimal counseling and care for individuals and families with HCM, awareness and education around HCM and genetic services should be promoted in both physicians and patients alike.

Clinical whole-exome sequencing: are we there yet?

BACKGROUND: Clinical laboratories began offering whole-exome sequencing in 2011 at a cost between $4,500 and $9,000. Reported detection rates for deleterious mutations range from 25 to 50%. Based on the experience of our clinical genetics service, actual success rates may be lower than estimated rates. We report results from our own experience along with a survey of clinical geneticists to ascertain (i) current success rates for causal gene detection in a clinical setting; (ii) if there are insurance authorization issues; and (iii) if turnaround times quoted by the clinical laboratories are accurate; we also gauge provider opinions toward clinical whole-exome sequencing. METHODS: We reviewed our results and the results of a survey that was electronically distributed to 47 clinical genetics centers. RESULTS: A total of 35 exome reports were available. If all positive results are collated, we observe a success rate of 22.8%. One result incorrectly identified a known benign variant as pathogenic. Some insurers covered all testing, whereas others denied any insurance coverage. Only three (23.1%) of our reports were available within the laboratory's quoted turnaround times. More than 50% of clinicians queried in our survey had not ordered whole-exome sequencing at the current time, many stating concerns regarding interpretation, insurance coverage, and cost. CONCLUSION: Clinical whole-exome sequencing has proven diagnostic utility; however, currently many clinicians have concerns regarding interpretation of results, insurance coverage, and cost.

Assessing the integration of genomic medicine in genetic counseling training programs.

Medical genetics has entered a period of transition from genetics to genomics. Genetic counselors (GCs) may take on roles in the clinical implementation of genomics. This study explores the perspectives of program directors (PDs) on including genomic medicine in GC training programs, as well as the status of this integration. Study methods included an online survey, an optional one-on-one telephone interview, and an optional curricula content analysis. The majority of respondents (15/16) reported that it is important to include genomic medicine in program curricula. Most topics of genomic medicine are either "currently taught" or "under development" in all participating programs. Interview data from five PDs and one faculty member supported the survey data. Integrating genomics in training programs is challenging, and it is essential to develop genomics resources for curricula.

Integrated versus trial specific focus improves decision-making in older preschoolers.

This study explored the effect of integrated-focus (focusing on a depiction of overall gains/losses) versus trial-focus (focusing on gains/losses at each trial) on choice in a preschool variant of the Iowa Gambling task. Participants included 65 preschoolers (M = 47.82, SD = 7.29). Children completed two versions of the Preschool Gambling task, three cool executive function tasks, a moral reasoning task, and an affective perspective taking task. The results indicated that while the integrated-focus condition led to improvement in the awareness of the game, the condition effect was moderated by age for decision-making choice; older preschoolers showed improvement in decision-making in the integrated focus condition, while younger preschoolers showed no condition effect. Further analysis indicated that differences in the increase of advantageous choice across blocks and the condition effect were partly explained by these differences in awareness. Furthermore, a component of cool executive function (shifting) was associated with the latter phase of decision-making. The findings additionally indicated an association of advantageous decision-making with moral/emotional measures, suggesting that the PGT may be a potentially useful clinical tool for early assessment. Finally, the findings of the current study have implications for how hot and cool executive function abilities may work together to enable adaptive decisions.

Rates and Classification of Variants of Uncertain Significance in Hereditary Disease Genetic Testing.

Importance: Variants of uncertain significance (VUSs) are rampant in clinical genetic testing, frustrating clinicians, patients, and laboratories because the uncertainty hinders diagnoses and clinical management. A comprehensive assessment of VUSs across many disease genes is needed to guide efforts to reduce uncertainty. Objective: To describe the sources, gene distribution, and population-level attributes of VUSs and to evaluate the impact of the different types of evidence used to reclassify them. Design, Setting, and Participants: This cohort study used germline DNA variant data from individuals referred by clinicians for diagnostic genetic testing for hereditary disorders. Participants included individuals for whom gene panel testing was conducted between September 9, 2014, and September 7, 2022. Data were analyzed from September 1, 2022, to April 1, 2023. Main Outcomes and Measures: The outcomes of interest were VUS rates (stratified by age; clinician-reported race, ethnicity, and ancestry groups; types of gene panels; and variant attributes), percentage of VUSs reclassified as benign or likely benign vs pathogenic or likely pathogenic, and enrichment of evidence types used for reclassifying VUSs. Results: The study cohort included 1 689 845 individuals ranging in age from 0 to 89 years at time of testing (median age, 50 years), with 1 203 210 (71.2%) female individuals. There were 39 150 Ashkenazi Jewish individuals (2.3%), 64 730 Asian individuals (3.8%), 126 739 Black individuals (7.5%), 5539 French Canadian individuals (0.3%), 169 714 Hispanic individuals (10.0%), 5058 Native American individuals (0.3%), 2696 Pacific Islander individuals (0.2%), 4842 Sephardic Jewish individuals (0.3%), and 974 383 White individuals (57.7%). Among all individuals tested, 692 227 (41.0%) had at least 1 VUS and 535 385 (31.7%) had only VUS results. The number of VUSs per individual increased as more genes were tested, and most VUSs were missense changes (86.6%). More VUSs were observed per sequenced gene in individuals who were not from a European White population, in middle-aged and older adults, and in individuals who underwent testing for disorders with incomplete penetrance. Of 37 699 unique VUSs that were reclassified, 30 239 (80.2%) were ultimately categorized as benign or likely benign. A mean (SD) of 30.7 (20.0) months elapsed for VUSs to be reclassified to benign or likely benign, and a mean (SD) of 22.4 (18.9) months elapsed for VUSs to be reclassified to pathogenic or likely pathogenic. Clinical evidence contributed most to reclassification. Conclusions and Relevance: This cohort study of approximately 1.6 million individuals highlighted the need for better methods for interpreting missense variants, increased availability of clinical and experimental evidence for variant classification, and more diverse representation of race, ethnicity, and ancestry groups in genomic databases. Data from this study could provide a sound basis for understanding the sources and resolution of VUSs and navigating appropriate next steps in patient care.

Marked variability in the radiographic features of cartilage-hair hypoplasia: case report and review of the literature.

Cartilage-hair hypoplasia (CHH) is a rare recessive metaphyseal chondrodysplasia characterized by severe short stature, ectodermal dysplasia, anemia in childhood, immune deficiency, susceptibility to malignancy, and normal intelligence. Short, thick long bones, metaphyseal flaring and irregularities, and globular epiphyses at the knees and ankles are the typical radiographic findings. The diagnosis is primarily made on the basis of clinical features, although mutations in the RMRP gene have recently been described in affected individuals, facilitating confirmation of the clinical diagnosis in atypical patients. We present a patient with two RMRP mutations whose stature and ectodermal features supported the diagnosis of CHH, but whose radiographic findings and other extraskeletal findings did not. We propose that the most consistent and reliable features of CHH are short stature of prenatal onset and ectodermal dysplasia, and suggest that the diagnosis of CHH be considered and mutation analysis pursued even when typical radiographic findings are absent.

Report of two patients and further characterization of interstitial 9p13 deletion--a rare but recurrent microdeletion syndrome?

To date, an interstitial deletion of 9p13 has been described only two times in the medical literature. These reports were based on routine chromosomal analysis. We report on two additional patients with an interstitial deletion of 9p13 further defined on array CGH who share clinical features with the other two patients previously described. Our first patient is a 16-year-old girl with a 5.9 Mb deletion at 9p13.3-9p13.1, initially detected on routine karyotype analysis and further characterized on array CGH. Our second patient is a 7½-year-old boy with a 4.8 Mb deletion also at 9p13.3-9p13.1. Patients with 9p13 deletion appear to have mild to moderate developmental delay, social and interactive personality, behavior issues such as attention deficit-hyperactivity disorder, short stature, prominent antihelices, hypoplastic nails, and precocious/early puberty. Our 16-year-old patient is the oldest patient described thus far. This report further characterizes this condition and helps to delineate the long-term prognosis in these patients.

Underutilization of genetics services for autism: the importance of parental awareness and provider recommendation.

Reasons for the underutilization of genetics services by families of children with autism spectrum disorders (ASD) are not well understood. We report the identification of factors associated with this underuse. Survey-based study of parents and/or guardians of children with ASD. One hundred fifty-five families completed the questionnaire. Thirty-one of 155 (20%) children had seen a genetics professional. Forty-nine of 154 (32%) children had undergone genetic testing. Parents whose child saw a genetics professional were more likely to 1) Have a primary provider refer for or suggest a genetics evaluation 2) Have asked for a referral, and/or 3) Know another person with a genetic cause of ASD. amilies of children with ASD who have not received genetics services are less aware of their availability and utility. They are also less likely to have their provider recommend a clinical genetics evaluation. Efforts should be taken to increase awareness of both health providers and parents regarding the usefulness of genetics services for ASD.

Ectopia lentis as the presenting and primary feature in Marfan syndrome.

Marfan syndrome (MFS) is a multisystem connective tissue disorder with primary involvement of the ocular, cardiovascular, and skeletal systems. We report on eight patients, all presenting initially with bilateral ectopia lentis (EL) during early childhood. These individuals did not have systemic manifestations of MFS, and did not fulfill the revised Ghent diagnostic criteria. However, all patients had demonstratable, disease-causing missense mutations in the FBN1 gene. Based on molecular results, cardiovascular imaging was recommended and led to the identification of mild aortic root changes in seven of the eight patients. The remaining patient had mitral valve prolapse with a normal appearing thoracic aorta. The findings presented in this paper validate the necessity of FBN1 gene testing in all individuals presenting with isolated EL. As we observed, these individuals are at increased risk of cardiovascular complications. Furthermore, we also noted that the majority of our patient cohort's mutations occurred in the 5' portion of the FBN1 gene, and were found to affect highly conserved cysteine residues, which may indicate a possible genotype-phenotype correlation. We conclude that in patients with isolated features of EL, FBN1 mutation analysis is necessary to aid in providing prompt diagnosis, and to identify patients at risk for potentially life-threatening complications. Additionally, knowledge of the type and location of an FBN1 mutation may be useful in providing further clinical correlation regarding phenotypic progression and appropriate medical management.

Clues to an early diagnosis of Kallmann syndrome.

Kallmann syndrome (KS) is defined by the association of idiopathic hypogonadotropic hypogonadism and anosmia/hyposmia. Diagnosis is frequently delayed, however, because hypogonadotropic hypogonadism is usually not apparent until puberty and individuals with anosmia/hyposmia are often unaware of this sensory deficit. Mutations in at least six genes have been associated with KS; however, the sensitivity of molecular testing is only about 30% and, therefore, the diagnosis is largely based on clinical findings. We describe the findings in six individuals with KS, which demonstrate the utility of associated anomalies in making this diagnosis. Analysis of our case series and literature review suggests the consideration of KS for males with microphallus and/or cryptorchidism and for any patient with hearing loss, renal agenesis, and/or synkinesis. Conversely, patients with features of KS should have an audiology evaluation and a renal ultrasound.

Clinical utility of array comparative genomic hybridization: uncovering tumor susceptibility in individuals with developmental delay.

Microarray-based comparative genomic hybridization can determine genome-wide copy number alterations at the kilobase level. We highlight the clinical utility of microarray-based comparative genomic hybridization in determining tumor susceptibility in 3 patients with dysmorphic features and developmental delay, likely decreasing both morbidity and mortality in these patients.

Hypoplastic glomerulocystic kidney disease and hepatoblastoma: a potential association not caused by mutations in hepatocyte nuclear factor 1beta.

Hypoplastic glomerulocystic kidney disease is an autosomal dominant disorder caused by mutations in hepatocyte nuclear factor-1beta. Hepatoblastoma is a sporadic occurring tumor of embryonal origin that has been associated with the several overgrowth syndromes. We report a case of concomitant hypoplastic glomerulocystic kidney disease and hepatoblastoma. Review of the literature identified 4 other patients with a similar association. We propose that hypoplastic glomerulocystic kidney disease and hepatoblastoma represent a possible association, and we excluded mutations in hepatocyte nuclear factor-1beta in our patient as causative of this putative association.

Lipoprotein abnormalities are associated with insulin resistance in South Asian Indian women.

South Asian Indians are at increased risk of coronary heart disease (CHD), possibly related to dyslipidemia characterized by high triglyceride (TG) and low high-density lipoprotein cholesterol (HDL-C) concentrations. The importance of differences in insulin resistance as compared to abdominal obesity in the development of this atherogenic lipoprotein profile is not clear, and the current cross-sectional study was initiated to examine this issue. Consequently, we defined the relationship between differences in insulin-mediated glucose uptake (IMGU), abdominal obesity, and various measures of lipoprotein metabolism known to increase CHD risk in 52 apparently healthy women of South Asian Indian ancestry. IMGU was quantified by determining the steady-state plasma glucose (SSPG) concentration during the insulin suppression test and abdominal obesity was assessed by measurement of waist circumference (WC), and the population was divided into tertiles on the basis of their SSPG results. Results indicated that although there were significant differences in SSPG, TG, and HDL-C values, there were no differences in age, blood pressure, total cholesterol, low-density lipoprotein cholesterol, body mass index, or WC between the highest and lowest tertiles. SSPG concentrations were significantly correlated with both log TG (r = 0.44, P = .001) and HDL-C (r = -0.44, P < .001) concentration, whereas TG and HDL-C concentrations were not significantly related to WC. Furthermore, the relationships between SSPG concentration and TG and HDL-C remained significant when adjusted for age and WC. Finally, a more extensive lipoprotein analysis indicated that the most insulin resistant tertile had higher TG concentrations, lower concentrations of HDL-C and HDL-C subclasses, and smaller and denser low-density lipoprotein particles than the most insulin sensitive tertile, despite the 2 groups not being different in age, BMI, or WC. These results indicate that a highly atherogenic lipoprotein profile seen in South Asian Indian women is significantly associated with insulin resistance independent of differences in WC.

Inhibition of phosphatidylinositol-3-kinase and mitogen-activated protein kinase kinase 1/2 prevents melanoma development and promotes melanoma regression in the transgenic TPRas mouse model.

A number of human melanomas show hyperactivation of the Ras pathway due to mutations of the molecule or alteration of upstream or downstream effectors. In this study, we evaluated the effect of blocking the two Ras downstream pathways phosphatidylinositol-3-kinase/Akt and Raf/mitogen-activated protein kinase kinase/extracellular signal-regulated kinase on melanoma development and regression in the TPRas mouse model. The inhibition of these two signaling cascades by topically applied Ly294002 and U0126 significantly delayed melanoma development and significantly decreased the tumor incidence, particularly when the drugs were applied in combination. Treatment with the inhibitors of established melanomas resulted in complete remission in 33% of mice and partial regression in 46% of mice when drugs were delivered in combination. These responses correlated with increased apoptosis and decreased proliferation both in vitro and in vivo and reduced tumor angiogenesis. In conclusion, this study strongly supports the role of the phosphatidylinositol-3-kinase/Akt and Raf/mitogen-activated protein kinase kinase/extracellular signal-regulated kinase pathways in the development and maintenance of Ras-dependent melanomas and supports the notion that specific inhibition of these effectors may represent a very promising avenue for the treatment and prevention of the disease.

Brachydactyly A-1 mutations restricted to the central region of the N-terminal active fragment of Indian Hedgehog.

Mutations in the gene Indian Hedgehog (IHH) that cause Brachydactyly A-1 (BDA1) have been restricted to a specific region of the N-terminal active fragment of Indian Hedgehog involving codons 95, 100, 131, and 154. We describe two novel mutations in codons 128 and 130, not previously implicated in BDA1. Furthermore, we identified an independent mutation at codon 131 and we also describe a New Zealand family, which carries the 'Farabee' founder mutation and haplotype. All of the BDA1 mutations occur in a restricted area of the N-terminal active fragment of the IHH and are in contrast to those mutations causing an autosomal recessive acrocapitofemoral dysplasia, whose mutations are located at the distal N- and C-terminal regions of IHH-N and are physically separated from the BDA1-causing mutations. The identification of multiple independent mutations in codons 95, 100, and now in 131, implicate a discrete function for this region of the protein. Finally, we present a clinical review of all reported and confirmed cases of BDA1, highlighting features of the disorder, which add to the spectrum of the IHH mutations.

Ethnic differences in the relationship between adiponectin and insulin sensitivity in South Asian and Caucasian women.

OBJECTIVE: To assess whether lower adiponectin concentrations in South Asian Indians may be responsible for their greater degree of insulin resistance. RESEARCH DESIGN AND METHODS: Insulin-mediated glucose uptake and plasma total and high molecular weight (HMW) adiponectin concentrations were quantified in 52 women of South Asian (SA) and Caucasian (CAU) ancestry and compared. RESULTS: Mean +/- SD total (2,965 +/- 1,278 vs. 4,235 +/- 160 ng/ml) and HMW (1,001 +/- 352 vs. 1,591 +/- 854 ng/ml) adiponectin were lower in SAs than CAUs (P < 0.005). Insulin-resistant CAUs (CAU-IR) had lower total (2,665 +/- 1,040 vs. 5,133 +/- 1,086 ng/ml) and HMW (987 +/- 479 vs. 1,935 +/- 838 ng/ml) adiponectin than insulin-sensitive CAUs (CAU-IS) (P < 0.01), but there were no significant differences between insulin-resistant (SA-IR) and insulin-sensitive (SA-IS) SAs. HMW adiponectin did not differ between SA-IR and CAU-IR, but SA-IS had significantly lower adiponectin concentrations than CAU-IS. CONCLUSIONS: Insulin resistance status is not associated with significantly lower levels of adiponectin in these SA women, in contrast to the CAU women.

Genitopatellar syndrome: expanding the phenotype and excluding mutations in LMX1B and TBX4.

Genitopatellar syndrome is a newly described disorder characterized by absent/hypoplastic patellae, lower extremity contractures, urogenital anomalies, dysmorphic features, skeletal anomalies, and agenesis of the corpus callosum. More recently, cardiac anomalies and ectodermal dysplasia have been suggested as additional features of this syndrome. We report on two additional patients with genitopatellar syndrome and expand the spectrum of anomalies to include radio-ulnar synostosis. Since there exists significant overlap in the skeletal phenotype between genitopatellar syndrome and both the nail-patella and short patella syndromes, mutation screening of their causative genes, LMX1B and TBX4, was performed. Although there still does not appear to be an identifiable molecular etiology in genitopatellar syndrome, mutations in these two candidate genes have been excluded in our patients. Since both LMX1B and TBX4 are involved in a common molecular pathway, it is likely that the causative gene of genitopatellar syndrome functions within the same developmental process.