Adaptation and validation of the Genetic Counseling Outcome Scale for autism spectrum disorders and related conditions.

The genetics care pathway experienced by families affected by autism spectrum disorder (ASD) around the time of diagnosis is currently uncharacterized and potentially variable across contexts. The lack of consensus on outcome measures to capture the impact of genetic services for these families shows a gap in understanding and optimizing this genetics care pathway. The Genetic Counseling Outcome Scale (GCOS-24) is a validated outcome measure of clinical genetics services. The current study aims to adapt and validate the GCOS-24 as an outcome measure in the context routine genetic testing in ASD and related conditions. Families seen for their child's developmental evaluation for ASD and related conditions were invited to participate in a genomics cohort between 2016 and 2018. Families (n = 111) completed the mGCOS-24 (modified GCOS-24), adapted from the original GCOS-24 by clinicians working in the target population's routine care pathway. The mGCOS-24 has acceptable internal consistency (Cronbach's α = 0.84) and high test-retest reliability (ICC = 0.88). It also inversely correlates with stress as measured by Perceived Stress Scale (PSS-10) and distress, as measured by the Distress Thermometer, rs ≥ 0.39, ps < 0.001. The mGCOS-24 had adequate readability, as supported by cognitive interviews completed by a sub-sample of five mothers of a child with ASD. Together, our findings show that the mGCOS-24 has good validity for the target population. Preliminary characterization of the genetics care pathway in this population revealed remarkable variability in pre-test counseling and limited post-test counseling. The use of the mGCOS-24 as an outcome measure is useful in filling some of these gaps by offering a way to assess, and in the future, optimize the genetics care pathway for families affected by autism and related neurodevelopmental conditions.

Membrane surface charge dictates the structure and function of the epithelial Na+/H+ exchanger.

The Na(+)/H(+) exchanger NHE3 plays a central role in intravascular volume and acid-base homeostasis. Ion exchange activity is conferred by its transmembrane domain, while regulation of the rate of transport by a variety of stimuli is dependent on its cytosolic C-terminal region. Liposome- and cell-based assays employing synthetic or recombinant segments of the cytosolic tail demonstrated preferential association with anionic membranes, which was abrogated by perturbations that interfere with electrostatic interactions. Resonance energy transfer measurements indicated that segments of the C-terminal domain approach the bilayer. In intact cells, neutralization of basic residues in the cytosolic tail by mutagenesis or disruption of electrostatic interactions inhibited Na(+)/H(+) exchange activity. An electrostatic switch model is proposed to account for multiple aspects of the regulation of NHE3 activity.

Novel interstitial deletion of 10q24.3-25.1 associated with multiple congenital anomalies including lobar holoprosencephaly, cleft lip and palate, and hypoplastic kidneys.

Chromosome 10q deletions are rare and phenotypically diverse. Such deletions differ in length and occur in numerous regions on the long arm of chromosome 10, accounting for the wide clinical variability. Commonly reported findings include dysmorphic facial features, microcephaly, developmental delay, and genitourinary abnormalities. Here, we report on a female patient with a novel interstitial 5.54 Mb deletion at 10q24.31-q25.1. This patient had findings in common with a previously reported patient with an overlapping deletion, including renal anomalies and an orofacial cleft, but also demonstrated lobar holoprosencephaly and a Dandy-Walker malformation, features which have not been previously reported with 10q deletions. An analysis of the region deleted in our patient showed numerous genes, such as KAZALD1, PAX2, SEMA4G, ACTRA1, INA, and FGF8, whose putative functions may have played a role in the phenotype seen in our patient.

Allelic heterogeneity and abnormal vesicle recycling in PLAA-related neurodevelopmental disorders.

The human PLAA gene encodes Phospholipase-A2-Activating-Protein (PLAA) involved in trafficking of membrane proteins. Through its PUL domain (PLAP, Ufd3p, and Lub1p), PLAA interacts with p97/VCP modulating synaptic vesicles recycling. Although few families carrying biallelic PLAA variants were reported with progressive neurodegeneration, consequences of monoallelic PLAA variants have not been elucidated. Using exome or genome sequencing we identified PLAA de-novo missense variants, affecting conserved residues within the PUL domain, in children affected with neurodevelopmental disorders (NDDs), including psychomotor regression, intellectual disability (ID) and autism spectrum disorders (ASDs). Computational and in-vitro studies of the identified variants revealed abnormal chain arrangements at C-terminal and reduced PLAA-p97/VCP interaction, respectively. These findings expand both allelic and phenotypic heterogeneity associated to PLAA-related neurological disorders, highlighting perturbed vesicle recycling as a potential disease mechanism in NDDs due to genetic defects of PLAA.

Microdeletion on 3p25 in a patient with features of 3p deletion syndrome.

The rare 3p deletion syndrome presents with a spectrum of anomalies caused by deletions of variable lengths within the short arm of chromosome 3. While most of these deletions involve the 3p terminus, interstitial deletions may also give rise to features of the syndrome. We have detected an interstitial deletion of 643 kb in a patient who displayed many of the typical 3p deletion features. This patient had a number of findings in common with a previously reported patient, who had a 1.6 Mb interstitial deletion, including cognitive handicap, seizures, and congenital heart defects. A 518 kb region of overlap containing 12 genes may prove to be a critical region for some of these features. The putative functions of several genes, such as CRELD1, SRGAP3, CAMK1, TADA3, and MTMR14 are discussed with respect to their potential involvement in the 3p deletion syndrome phenotype. We suggest that this 518 kb area of overlap may define a critical region, which when deleted, can give rise to the 3p deletion syndrome phenotype.

Enhancing the Impact of Genomics Research in Autism through Integration of Research Results into Routine Care Pathways-A Case Series.

The return of genetic results (RoR) to participants, enrolled as children, in autism research remains a complex process. Existing recommendations offer limited guidance on the use of genetic research results for clinical care. We highlight current challenges with RoR and illustrate how the use of a guiding framework drawn from existing literature facilitates RoR and the clinical integration of genetic research results. We report a case series (n = 16) involving the return of genetic results to participants in large genomics studies in Autism Spectrum Disorders (ASD). We outline the framework that guided RoR and facilitated integration into clinical care pathways. We highlight specific cases to illustrate challenges that were, or could have been, resolved through this framework. The case series demonstrates the ethical, clinical and practical difficulties of RoR in ASD genomic studies for participants enrolled as children. Challenges were resolved using pre-established framework to guide RoR and incorporate research genetic results into clinical care. We suggest that optimal use of genetic research results relies on their integration into individualized care pathways for participants. We offer a framework that attempts to bridge the gap between research and healthcare in ASD.

Predictors of empowerment in parents of children with autism and related neurodevelopmental disorders who are undergoing genetic testing.

BACKGROUND: There is limited empirical data quantifying the utility of genetic testing for families of children with autism spectrum disorder (ASD) or related neurodevelopmental disorders (NDD). We assessed the utility of clinical chromosomal microarray analysis (CMA), defined by diagnostic yield and parental empowerment, in population-based sample of parents of affected children; and explored child, family, and health services factors predictive of empowerment. METHODS: Participants were families of children undergoing diagnostic assessments, between 2016 and 2019. Diagnostic yield of CMA in affected children was determined. Parental empowerment was measured through adapted version of the Genetics Counseling Outcome Scale-24. Parents completed questionnaires to capture child, family, and health service factors. RESULTS: The diagnostic yield of CMA was 2.8% for pathogenic variants. Parental empowerment was significantly correlated with family functioning and aspects of perceived family-centeredness of care. The model accounted for 49.8% of the variation in parental empowerment, F (10,37) = 3.67, p = 0.002. After accounting for other predictors, parental perception of the provision of general information remained significantly associated with empowerment. CONCLUSION: The informational needs of families play an important role in their empowerment during genetic testing. Meeting these needs and monitoring empowerment can aid genomic technologies integration in personalized healthcare for ASD/NDD.

Novel and recurrent mutations in the C1NH gene of Arab patients affected with hereditary angioedema.

BACKGROUND: Autosomal dominant hereditary angioedema (HAE) results in episodes of subcutaneous edema in any body part and/or submucosal edema of the upper respiratory or gastrointestinal tracts. This disorder is caused by mutations in the C1NH gene, many of which have been described primarily in European patients. However, the genetic cause of HAE in Middle Eastern Arab patients has not yet been determined. METHODS: Four unrelated Arab families, in which 15 patients were diagnosed with HAE, were studied. DNA from 13 patients was analyzed for mutations in the C1NH gene by DNA sequencing. RESULTS: Three novel and 2 recurrent mutations were identified in the C1NH gene of HAE patients. In family 1, the patient was heterozygous for a novel c.856C>T and a recurrent c.1361T>A missense mutation encoding for p.Arg264Cys and p.Val432Glu, respectively. In patients from family 2, a novel c.509C>T missense mutation encoding for a p.Ser148Phe was identified. In patients from family 3, a novel c.1142delC nonsense mutation encoding for a p.Ala359AlafsX15 was discovered. In family 4, a recurrent c.1397G>A missense mutation encoding for a p.Arg444His was present. CONCLUSION: This is the first ever report of C1NH gene mutations in Middle Eastern Arab patients. Our study suggests that, despite the numerous existing mutations in the C1NH gene, there are novel and recurrent mutations in HAE patients of non-European origin. We conclude that the spectrum of C1NH gene mutations in HAE patients is wider due to the likely presence of novel and recurrent mutations in patients of other ethnicities.

A novel HAX1 gene mutation in severe congenital neutropenia (SCN) associated with neurological manifestations.

Autosomal recessive severe congenital neutropenia (SCN) results from a maturation arrest of granulopoiesis at the level of promyelocytes and apoptosis of myeloid cells. In SCN patients, mutations have been described in the HAX1 gene. Most of the SCN patients who carry nonsense mutations that are common to both transcript variants of the HAX1 gene also exhibit neurological deficits. This study describes an SCN patient with neurological manifestations including daily episodes of atonic seizures, learning disabilities, and developmental delay. Sequencing of the HAX1 gene of this SCN patient identified a novel nonsense c.463_464insC homozygous mutation in exon 3, which is common to both transcript variants of the gene. This mutation encodes for a p.Gln155ProfsX14 change and causes premature truncation of the HAX1 protein. Neutrophils isolated from the patient exhibited spontaneous apoptosis and loss of inner mitochondrial membrane potential, which were further enhanced upon treatment with hydrogen peroxide. This study adds to the spectrum of novel HAX1 gene mutations and disease manifestations in ethnically distinct SCN patients. Our report describes the only nonsense mutation in the HAX1 gene present in SCN patients of Arab origin.

Perceived utility of biological testing for autism spectrum disorder is associated with child and family functioning.

BACKGROUND: The clinical integration of chromosomal microarray testing promises improvements in diagnostic yields in Autism Spectrum Disorder (ASD). While the impact on clinical management is promising for some families, the utility perceived by families, including the majority for whom results are negative, is unclear. With next generation genomic sequencing technologies poised for integration, along with promising ASD biomarkers being developed, there is a need to understand the extent to which genomic and other biological testing would have utility for the target recipients of these tests and their families. The purpose of the present cross-sectional study was to examine the predictors of perceived utility of biological testing among parents of a child with ASD. METHODS: The Perceived Utility of Biotesting (PUB) Questionnaire was developed based on literature review and integrating family review. Following their child's diagnosis, families participating in an ongoing prospective study completed the PUB questionnaire along with self-reported measures of parent stress, child and family functioning, and family-centered care prior to undergoing genetic testing for both clinical and research purposes. RESULTS: Based on n = 85 families, psychometric properties of the Perceived Utility of Biotesting questionnaire suggest a reliable and valid instrument. A stepwise regression analysis reveals that lower levels of child emotional and behavioural functioning and higher levels of family functioning correlated with higher perceived utility for biological testing. LIMITATIONS: A main limitation in the study is the participation rate of 50 %, thus the possibility of self-selection bias cannot be ruled out. We also chose to assess perceived utility among parents rather than the individuals with ASD themselves: modifying the questionnaire to capture perceived utility from autistic individuals across the lifespan would prove essential in future studies. Finally, ongoing validation of the PUB by assessing the PUB's discriminant and convergent validity is still needed. CONCLUSIONS: We conclude that the utility of biological testing perceived by families whose child is undergoing genetic testing around ASD diagnosis depends on their unique child and family characteristics. This signifies that engaging families in biomarker discovery for improving the impact of research and care requires systematic input from a representative sample of families.

Novel FBP1 gene mutations in Arab patients with fructose-1,6-bisphosphatase deficiency.

UNLABELLED: Deficiency of fructose-1,6-bisphosphatase (FBP) results in impaired gluconeogenesis, which is characterized by episodes of hyperventilation, apnea, hypoglycemia, and metabolic and lactic acidosis. This autosomal recessive disorder is caused by mutations in the FBP1 gene, which encodes for fructose-1,6-bisphosphatase 1 (FBP1). Although FBP1 gene mutations have been described in FBP-deficient individuals of various ethnicities, there has been limited investigation into the genetics of this disorder in Arab patients. This study employed five consanguineous Arab families, in which 17 patients were clinically diagnosed with FBP deficiency. Seven patients and six carrier parents were analyzed for mutations in the FBP1 gene. DNA sequencing of the FBP1 gene identified two novel mutations in these families. A novel six nucleotide repetitive insertion, c114_119dupCTGCAC, was identified in patients from three families. This mutation encodes for a duplication of two amino acids (p.Cys39_Thr40dup) in the N-terminal domain of FBP1. A novel nonsense c.841G>T mutation encoding for a p.Glu281X truncation in the active site of FBP1 was discovered in patients from two families. The newly identified mutations in the FBP1 gene are predicted to produce FBP1 deficiency. These mutations are the only known genetic causes of FBP deficiency in Arab patients. The p.Cys39_Thr40dup is the first reported amino acid duplication in FBP deficiency patients. CONCLUSION: This study provides a strong rationale for genetic testing of FBP deficient patients of Arab ethnicity for recurrent or novel mutations in the FBP1 gene.

Association between distress and knowledge among parents of autistic children.

Understanding the overall utility of biological testing for autism spectrum disorder (ASD) is essential for the development and integration of biomarkers into routine care. One measure related to the overall utility of biological testing is the knowledge that a person has about the condition he/she suffers from. However, a major gap towards understanding the role of knowledge in overall utility is the absence of studies that have assessed knowledge of autism along with its predictors within a representative sample of families within the context of routine care. The objective of this study was to measure knowledge of ASD among families within the routine care pathway for biological testing in ASD by examining the association between knowledge with potential correlates of knowledge namely sociodemographic factors, parental stress and distress, and time since diagnosis among parents whose child with ASD is undergoing clinical genetic testing. Parents of a child diagnosed with ASD (n = 85, Mage = 39.0, SD = 7.7) participating in an ongoing prospective genomics study completed the ASD Quiz prior to undergoing genetic testing for clinical and research purposes. Parents also completed self-reported measures of stress and distress. Parent stress and distress was each independently correlated with knowledge of ASD, rs ≥ 0.26, ps < 0.05. Stepwise regression analysis revealed a significant model accounting for 7.8% of the variance in knowledge, F (1, 82) = 8.02, p = 0.006. The only factor significantly associated with knowledge was parental distress, ß = 0.30, p = 0.006. Parental stress, time since diagnosis, and sociodemographic factors were not significant predictors in this model. We concluded that families require tailored support prior to undergoing genetic testing to address either knowledge gaps or high distress. Ongoing appraisal of the testing process among families of diverse backgrounds is essential in offering optimal care for families undergoing genetic testing.

Spectrum of the KIT Gene Mutations in Gastrointestinal Stromal Tumors in Arab Patients

Background: Gastrointestinal stromal tumors are the most common mesenchymal tumors of the gastrointestinal tract, which originate from the interstitial cells of Cajal. These tumors are characterized by expression of CD117 and CD34 antigens and activating mutations in the KIT and PDGFRA genes. While KIT and PDGFRA mutations have been extensively studied in other populations, the spectrum of mutations in Arab patients remains unknown. The study aimed at determining the distribution of KIT and PDGFRA mutations and phenotypic characterization of the gastrointestinal stromal tumors in Arab patients. Methods: Sanger sequencing was used to analyze 52 archived gastrointestinal stromal tumors for mutations in the KIT and the PDGFRA genes. Tumor descriptions were obtained from the clinical reports of patients. Results: In these patients, most tumors occur in the stomach, followed by the rest of the digestive tract. A vast majority of tumors express the CD117 and CD34 antigens. Sequencing of the KIT and PDGFRA genes identified five non-synonymous mutations and 26 deletions (25 novel) in exon 11 of the KIT gene. All non-synonymous mutations and deletions affect the juxta-membrane domain, which is known to inhibit ligand-independent activation of the KIT receptor. No mutations were found in the PDGFRA gene. Conclusions: Molecular profiling of the gastrointestinal stromal tumors in Arab patients identified a unique spectrum of mutations in exon 11 of the KIT gene. These data are important for the diagnosis and management of patients of Arab ethnic origin.

Clinical, neuroimaging, and genetic features of L-2-hydroxyglutaric aciduria in Arab kindreds.

BACKGROUND AND OBJECTIVES: L-2-hydroxyglutaric aciduria is a neurometabolic disorder with autosomal recessive mode of inheritance in which patients exhibit elevated L-2-hydroxyglutaric acid in body fluids, central nervous system manifestations, and increased risk of brain tumor formation. Mutations in L2HGDH gene have been described in L-2-hydroxyglutaric aciduria patients of different ethnicities. The present study was conducted to perform a detailed clinical, imaging and genetic analysis. DESIGN AND SETTINGS: A cross-sectional clinical genetic study of 16 L-2-hydroxyglutaric aciduria patients from 4 Arab consanguineous families examined at the metabolic clinic of the hospital. PATIENTS AND METHODS: Genomic DNA was isolated from the blood of 12 patients and 10 unaffected family members, and the L2HGDH gene was sequenced. DNA sequences were compared to the L2HGDH reference sequence from GenBank. RESULTS: All patients exhibit characteristic clinical, biochemical, and imaging features of L-2-hydroxyglutaric aciduria, and 4 patients exhibited increased incidence of brain tumors. The sequencing of the L2HGDH gene revealed the c.1015delA, c.1319C > A, and c.169G > A mutations in these patients. These mutations encode for the p.Arg339AspfsX351, p.Ser440Tyr, and p.Gly57Arg changes in the L2HGDH protein, respectively. The c.169G > A mutation, which was shown to have a common origin in Italian and Portuguese patients, was also discovered in Arab patients. Finding of the homozygous c.159T SNP associated with the c.169G > A mutation in Arab patients points to an independent origin of this mutation in Arab population. CONCLUSION: The detailed description of clinical manifestations and L2HGDH mutation in this study is useful for diagnosis of L-2-hydroxyglutaric aciduria in Arab patients. While reoccurrence of an L2HGDH mutation in L-2-hydroxyglutaric aciduria patients of different ethnicity is extremely rare, the c.169G mutation has an independent origin in Arab patients. It is likely that this mutation may also be present in patients of other ethnicities.