Bi-allelic disruptive variants (nonsense, frameshift, and splicing variants) in KDM5B have been identified as causative for autosomal recessive intellectual developmental disorder type 65. In contrast, dominant variants, usually disruptive as well, have been more difficult to implicate in a specific phenotype, since some of them have been found in unaffected controls or relatives. Here, we describe individuals with likely pathogenic variants in KDM5B, including eight individuals with dominant missense variants. This study is a retrospective case series of 21 individuals with variants in KDM5B. We performed deep phenotyping and collected the clinical information and molecular data of these individuals’ family members. We compared the phenotypes according to variant type and to those previously described in the literature. The most common features were developmental delay, impaired intellectual development, behavioral problems, autistic behaviors, sleep disorders, facial dysmorphism, and overgrowth. DD, ASD behaviors, and sleep disorders were more common in individuals with dominant disruptive KDM5B variants, while individuals with dominant missense variants presented more frequently with renal and skin anomalies. This study extends our understanding of the KDM5B-related neurodevelopmental disorder and suggests the pathogenicity of certain dominant KDM5B missense variants.
Further delineation of the rare GDACCF (global developmental delay, absent or hypoplastic corpus callosum, dysmorphic facies syndrome): genotype and phenotype of 22 patients with ZNF148 mutations
Background Pathogenic variants in the zinc finger protein coding genes are rare causes of intellectual disability and congenital malformations. Mutations in the ZNF148 gene causing GDACCF syndrome (global developmental delay, absent or hypoplastic corpus callosum, dysmorphic facies; MIM #617260) have been reported in five individuals so far. Methods As a result of an international collaboration using GeneMatcher Phenome Central Repository and personal communications, here we describe the clinical and molecular genetic characteristics of 22 previously unreported individuals. Results The core clinical phenotype is characterised by developmental delay particularly in the domain of speech development, postnatal growth retardation, microcephaly and facial dysmorphism. Corpus callosum abnormalities appear less frequently than suggested by previous observations. The identified mutations concerned nonsense or frameshift variants that were mainly located in the last exon of the ZNF148 gene. Heterozygous deletion including the entire ZNF148 gene was found in only one case. Most mutations occurred de novo, but were inherited from an affected parent in two families. Conclusion The GDACCF syndrome is clinically diverse, and a genotype-first approach, that is, exome sequencing is recommended for establishing a genetic diagnosis rather than a phenotype-first approach. However, the syndrome may be suspected based on some recurrent, recognisable features. Corpus callosum anomalies were not as constant as previously suggested, we therefore recommend to replace the term ‘GDACCF syndrome’ with ‘ZNF148-related neurodevelopmental disorder’.
Examining career shadowing in genetic counseling: Perspectives of shadowees, program directors, and genetic counselors
Abstract Career shadowing can be a valuable opportunity for individuals to experience the daily activities of a working professional. However, there is no published research regarding the impact of shadowing for individuals hoping to pursue a career as a genetic counselor (GC) (termed ‘shadowees’). Additionally, little is known about the impact of shadowing on practicing GCs, nor the value of shadowing in the application and admission process for genetic counseling graduate programs. For this study, three independent surveys were developed and sent to three stakeholder groups: shadowees in the Minnesota Genetic Counseling Experience Program, program directors within the Association of Genetic Counseling Program Directors, and members of the National Society of Genetic Counselors. Quantitative and qualitative analyses were performed on responses. The survey of shadowees ( n = 55) found that the majority believed that shadowing had either a ‘very’ or ‘somewhat positive’ impact on their decision to become a GC and on their application to a genetic counseling graduate program (81.8% and 91.3%, respectively). Of the participating program director respondents ( n = 43), the majority indicated that having shadowing experience was either ‘moderately’ or ‘extremely important’ in offering an interview or for acceptance into a graduate program (63% and 56%, respectively). While programs differ in evaluation of shadowing experiences, most program directors indicated that an applicant's ability to speak to their shadowing experience was the most important factor in admissions consideration (71%). Among the GCs surveyed ( n = 325), 69.2% have hosted shadowees; of these, 82.7% indicated that hosting a shadowee decreases their efficiency at work. Despite this drawback, the majority of respondents expressed a willingness and motivation to host shadowees to help the shadowee (64.8%) and to promote the genetic counseling profession (32.6%). These findings suggest the need for additional research and the development of resources for GCs to increase access of career shadowing.
Developmental brain abnormalities and acute encephalopathy in a patient with myopathy with extrapyramidal signs secondary to pathogenic variants in MICU1
AbstractMitochondria play a variety of roles in the cell, far beyond their widely recognized role in ATP generation. One such role is the regulation and sequestration of calcium, which is done with the help of the mitochondrial calcium uniporter (MCU) and its regulators, MICU1 and MICU2. Genetic variations in MICU1 and MICU2 have been reported to cause myopathy, developmental disability and neurological symptoms typical of mitochondrial disorders. The symptoms of MICU1/2 deficiency have generally been attributed to calcium regulation in the metabolic and biochemical roles of mitochondria. Here, we report a female child with heterozygous MICU1 variants and multiple congenital brain malformations on MRI. Specifically, she shows anterior perisylvian polymicrogyria, dysmorphic basal ganglia, and cerebellar dysplasia in addition to white matter abnormalities. These novel findings suggest that MICU1 is necessary for proper neurodevelopment through a variety of potential mechanisms, including calcium‐mediated regulation of the neuronal cytoskeleton, Miro1‐MCU complex‐mediated mitochondrial movement, or enhancing ATP production. This case provides new insight into the molecular pathogenesis of MCU dysfunction and may represent a novel diagnostic feature of calcium‐based mitochondrial disease.
Deficient histone H3 propionylation by BRPF1-KAT6 complexes in neurodevelopmental disorders and cancer
Abstract Alopecia areata (AA), a complex autoimmune hair loss condition, affects approximately 2.1% of the population. Individuals with AA have increased susceptibility to diseases such as atopy and autoimmune disorders, but little is known about first‐degree relatives' risk to develop AA and associated conditions. Genetic counseling for multifactorial conditions, including autoimmune disease is complex, but potentially valuable. Anecdotally we know patients with AA ask medical providers about recurrence risk for family members as well as question whether they and their relatives are at risk for other conditions. Data on AA recurrence risks and comorbid conditions among relatives of affected individuals comprise valuable information that may guide clinical management by genetic counselors. This study investigated the recurrence risk of AA and compared the prevalence of associated conditions among first‐degree relatives to the general population. The study also assessed the validity of self‐reported conditions for a subset of participants. Relatives of individuals with AA ( N = 155), recruited from the National Alopecia Areata Foundation Registry, completed telephone surveys about their personal medical history for 70 medical conditions associated with AA. Medical records for 60 participants were compared to self‐reported responses. One‐sided proportional tests, in which it is assumed the disease prevalence in first‐degree relatives is higher than for those in the general population, yielded a 7.8% estimated risk of AA versus the general population prevalence of 2.1%. Furthermore, there are increased risks of 33 associated conditions, including atopy and other autoimmune conditions. Comparison of medical reports to self‐reported conditions indicated only 12% was incongruent. The findings may help genetic counselors better serve patients and their families by informing them of lifetime risk estimates of developing AA and comorbid conditions, resulting in early diagnosis of autoimmune diseases in AA families. Findings also provide evidence supporting the validity of self‐report data in AA families.
Perspectives on facilitating whole exome sequencing for international patients at Mayo Clinic
AbstractWhole exome sequencing (WES) has become a fundamental component of genetic evaluation and diagnosing rare genetic diseases. This test is now offered to patients from a wide variety of cultural backgrounds and in various clinical and research settings. This commentary is a reflection of one group of clinical genetic counselors’ experiences in facilitating WES for patients who come from outside the United States for genetic evaluation and pursue WES. This patient population in our clinic primarily consists of individuals from the Middle East and presents recurrent logistical and counseling challenges. We aim to describe our international patient population, illuminate the challenges we have faced and illustrate how we have addressed these challenges.