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Haploinsufficiency of TRIP12 causes a neurodevelopmental disorder characterized by intellectual disability associated with epilepsy, autism spectrum disorder and dysmorphic features, also named Clark-Baraitser syndrome. Only a limited number of cases have been reported to date. We aimed to further delineate the TRIP12-associated phenotype and objectify characteristic facial traits through GestaltMatcher image analysis based on deep-learning algorithms in order to establish a TRIP12 gestalt. 38 individuals between 3 and 66 years (F = 20, M = 18) - 1 previously published and 37 novel individuals - were recruited through an ERN ITHACA call for collaboration. 35 TRIP12 variants were identified, including frameshift (n = 15) and nonsense (n = 6) variants, as well as missense (n = 5) and splice (n = 3) variants, intragenic deletions (n = 4) and two multigene deletions disrupting TRIP12. Though variable in severity, global developmental delay was noted in all individuals, with language deficit most pronounced. About half showed autistic features and susceptibility to obesity seemed inherent to this disorder. A more severe expression was noted in individuals with a missense variant. Facial analysis showed a clear gestalt including deep-set eyes with narrow palpebral fissures and fullness of the upper eyelids, downturned corners of the mouth and large, often low-set ears with prominent earlobes. We report the largest cohort to date of individuals with TRIP12 variants, further delineating the associated phenotype and introducing a facial gestalt. These findings will improve future counseling and patient guidance.

Background and ObjectivesKCNH5encodes the voltage-gated potassium channel EAG2/Kv10.2. We aimed to delineate the neurodevelopmental and epilepsy phenotypic spectrum associated with de novoKCNH5variants.MethodsWe screened 893 individuals with developmental and epileptic encephalopathies forKCNH5variants using targeted or exome sequencing. Additional individuals withKCNH5variants were identified through an international collaboration. Clinical history, EEG, and imaging data were analyzed; seizure types and epilepsy syndromes were classified. We included 3 previously published individuals including additional phenotypic details.ResultsWe report a cohort of 17 patients, including 9 with a recurrent de novo missense variant p.Arg327His, 4 with a recurrent missense variant p.Arg333His, and 4 additional novel missense variants. All variants were located in or near the functionally critical voltage-sensing or pore domains, absent in the general population, and classified as pathogenic or likely pathogenic using the American College of Medical Genetics and Genomics criteria. All individuals presented with epilepsy with a median seizure onset at 6 months. They had a wide range of seizure types, including focal and generalized seizures. Cognitive outcomes ranged from normal intellect to profound impairment. Individuals with the recurrent p.Arg333His variant had a self-limited drug-responsive focal or generalized epilepsy and normal intellect, whereas the recurrent p.Arg327His variant was associated with infantile-onset DEE. Two individuals with variants in the pore domain were more severely affected, with a neonatal-onset movement disorder, early-infantile DEE, profound disability, and childhood death.DiscussionWe describe a cohort of 17 individuals with pathogenic or likely pathogenic missense variants in the voltage-sensing and pore domains of Kv10.2, including 14 previously unreported individuals. We present evidence for a putative emerging genotype-phenotype correlation with a spectrum of epilepsy and cognitive outcomes. Overall, we expand the role of EAG proteins in human disease and establishKCNH5as implicated in a spectrum of neurodevelopmental disorders and epilepsy.

Keratinocyte differentiation factor (KDF)1 has been shown to cause ectodermal dysplasia with or without hidradenitis suppurativa in a single family. KDF1 is known to regulate epidermal differentiation through its interaction with IκB kinase (IKK)α. We report a novel de novo KDF1 variant (p.His254Tyr) in a 20-year-old male patient presenting with hidradenitis suppurativa and ectodermal dysplasia. We demonstrate that variants in KDF1 associated with hidradenitis suppurativa actually cause pathogenic gain-of-function of KDF1 through upregulation of IKKα. Ectodermal dysplasia may be present in a subset of individuals with hidradenitis suppurativa and should be investigated. Inhibition of IKKα appears to be a suitable therapeutic target for these individuals.

Zinc is an essential trace mineral. Dietary zinc deficiency results in stunted growth, skin lesions, hypogonadism and frequent infections in humans. Mice genetically lacking Slc30a7 suffer from mild zinc deficiency and are prone to development of prostate cancer and insulin resistance. Disease-causing variants or mutations in the human SLC30A7 (ZNT7) gene have not been previously reported. Here, we describe two-boy siblings from a French family with stunted growth, testicular hypoplasia and bone marrow failure. Exome sequencing revealed compound heterozygous variants in ZNT7 consisting of NM_133496.5:c.21dup; p.Asp8ArgfsTer3 and c.842 + 15 T > C inherited from their unaffected mother and father, respectively. The c.21dup variant led to a premature stop codon generated in exon 1 of the ZNT7 coding sequence. RNA-seq analysis demonstrated that the c.842 + 15 T > C variant resulted in a leaky mRNA splicing event generating a premature stop codon right after the splicing donor site of exon 8. Moreover, the expression of ZNT7 protein was remarkably reduced by 80–96% in the affected brothers compared to the control cells. These findings strongly suggest that biallelic variants in SLC30A7 should be considered as a cause of growth retardation, testicular hypoplasia and syndromic bone marrow failure.

ObjectiveKCNH5 encodes the voltage-gated potassium channel EAG2/Kv10.2. We aimed to delineate the neurodevelopmental and epilepsy phenotypic spectrum associated with de novo KCNH5 variants.MethodsWe screened 893 individuals with developmental and epileptic encephalopathies (DEEs) for KCNH5 variants using targeted or exome sequencing. Additional individuals with KCNH5 variants were identified through an international collaboration. Clinical history, EEG, and imaging data were analyzed; seizure types and epilepsy syndromes were classified. We included three previously published individuals including additional phenotypic details.ResultsWe report a cohort of 17 patients, including nine with a recurrent de novo missense variant p.Arg327His, four with a recurrent missense variant p.Arg333His, and four additional novel missense variants. All variants were located in or near the functionally critical voltage-sensing or pore domains, absent in the general population, and classified as pathogenic or likely pathogenic using American College of Medical Genetics and Genomics (ACMG) criteria. All individuals presented with epilepsy with a median seizure onset at six months. They had a wide range of seizure types, including focal and generalized seizures. Cognitive outcomes ranged from normal intellect to profound impairment. Individuals with the recurrent p.Arg333His variant had a self-limited drug-responsive focal or generalised epilepsy and normal intellect, while the recurrent p.Arg327His variant was associated with infantile-onset DEE. Two individuals with variants in the pore-domain were more severely affected, with neonatal-onset DEE, profound disability, and childhood death.ConclusionsWe report the first cohort of 17 individuals with pathogenic or likely pathogenic missense variants in the voltage sensing and pore domains of Kv10.2, including 14 previously unreported individuals. We present evidence for a putative emerging genotype-phenotype correlation with a spectrum of epilepsy and cognitive outcomes. Overall, we expand the role of EAG proteins in human disease and establish KCNH5 as implicated in a spectrum of neurodevelopmental disorders (NDDs) and epilepsy.

© 2022 American College of Medical Genetics and GenomicsPurpose: Pathogenic variants in genes encoding ubiquitin E3 ligases are known to cause neurodevelopmental syndromes. Additional neurodevelopmental disorders associated with the other genes encoding E3 ligases are yet to be identified. Methods: Chromosomal analysis and exome sequencing were used to identify the genetic causes in 10 patients from 7 unrelated families with syndromic neurodevelopmental, seizure, and movement disorders and neurobehavioral phenotypes. Results: In total, 4 patients were found to have 3 different homozygous loss-of-function (LoF) variants, and 3 patients had 4 compound heterozygous missense variants in the candidate E3 ligase gene, HECTD4, that were rare, absent from controls as homozygous, and predicted to be deleterious in silico. In 3 patients from 2 families with Angelman-like syndrome, paralog-directed candidate gene approach detected 2 LoF variants in the other candidate E3 ligase gene, UBE3C, a paralog of the Angelman syndrome E3 ligase gene, UBE3A. The RNA studies in 4 patients with LoF variants in HECTD4 and UBE3C provided evidence for the LoF effect. Conclusion: HECTD4 and UBE3C are novel biallelic rare disease genes, expand the association of the other HECT E3 ligase group with neurodevelopmental syndromes, and could explain some of the missing heritability in patients with a suggestive clinical diagnosis of Angelman syndrome.