scholarly journals TCF12 haploinsufficiency causes autosomal dominant Kallmann syndrome and reveals network-level interactions between causal loci

2020 ◽  
Vol 29 (14) ◽  
pp. 2435-2450
Author(s):  
Erica E Davis ◽  
Ravikumar Balasubramanian ◽  
Zachary A Kupchinsky ◽  
David L Keefe ◽  
Lacey Plummer ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Autosomal Dominant ◽  
Kallmann Syndrome ◽  
Gonadotropin Releasing Hormone ◽  
Loss Of Function ◽  
Binding Partner ◽  
Zebrafish Larvae ◽  
Syndromic Craniosynostosis ◽  
Molecular Components

Abstract Dysfunction of the gonadotropin-releasing hormone (GnRH) axis causes a range of reproductive phenotypes resulting from defects in the specification, migration and/or function of GnRH neurons. To identify additional molecular components of this system, we initiated a systematic genetic interrogation of families with isolated GnRH deficiency (IGD). Here, we report 13 families (12 autosomal dominant and one autosomal recessive) with an anosmic form of IGD (Kallmann syndrome) with loss-of-function mutations in TCF12, a locus also known to cause syndromic and non-syndromic craniosynostosis. We show that loss of tcf12 in zebrafish larvae perturbs GnRH neuronal patterning with concomitant attenuation of the orthologous expression of tcf3a/b, encoding a binding partner of TCF12, and stub1, a gene that is both mutated in other syndromic forms of IGD and maps to a TCF12 affinity network. Finally, we report that restored STUB1 mRNA rescues loss of tcf12 in vivo. Our data extend the mutational landscape of IGD, highlight the genetic links between craniofacial patterning and GnRH dysfunction and begin to assemble the functional network that regulates the development of the GnRH axis.

scholarly journals ANK3 related neurodevelopmental disorders: expanding the spectrum of heterozygous loss-of-function variants

Neurogenetics ◽  
2021 ◽  
Author(s):  
Katja Kloth ◽  
Bernarda Lozic ◽  
Julia Tagoe ◽  
Mariëtte J. V. Hoffer ◽  
Amelie Van der Ven ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Neuronal Development ◽  
Autosomal Dominant ◽  
Tissue Expression ◽  
Autism Spectrum ◽  
Loss Of Function ◽  
Ankyrin G ◽  
Phenotypic Spectrum ◽  
And Function ◽  
Neurodevelopmental Phenotype

AbstractANK3 encodes multiple isoforms of ankyrin-G, resulting in variegated tissue expression and function, especially regarding its role in neuronal development. Based on the zygosity, location, and type, ANK3 variants result in different neurodevelopmental phenotypes. Autism spectrum disorder has been associated with heterozygous missense variants in ANK3, whereas a more severe neurodevelopmental phenotype is caused by isoform-dependent, autosomal-dominant, or autosomal-recessive loss-of-function variants. Here, we present four individuals affected by a variable neurodevelopmental phenotype harboring a heterozygous frameshift or nonsense variant affecting all ANK3 transcripts. Thus, we provide further evidence of an isoform-based phenotypic continuum underlying ANK3-associated pathologies and expand its phenotypic spectrum.

scholarly journals DJ-1 regulates the integrity and function of ER-mitochondria association through interaction with IP3R3-Grp75-VDAC1

2019 ◽  
Vol 116 (50) ◽  
pp. 25322-25328 ◽  
Author(s):  
Yi Liu ◽  
Xiaopin Ma ◽  
Hisashi Fujioka ◽  
Jun Liu ◽  
Shengdi Chen ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Cellular Mechanism ◽  
Loss Of Function ◽  
Wild Type ◽  
Calcium Efflux ◽  
And Function ◽  
The Brain ◽  
Early Onset Parkinson’S Disease

Loss-of-function mutations in DJ-1 are associated with autosomal recessive early onset Parkinson’s disease (PD), yet the underlying pathogenic mechanism remains elusive. Here we demonstrate that DJ-1 localized to the mitochondria-associated membrane (MAM) both in vitro and in vivo. In fact, DJ-1 physically interacts with and is an essential component of the IP3R3-Grp75-VDAC1 complexes at MAM. Loss of DJ-1 disrupted the IP3R3-Grp75-VDAC1 complex and led to reduced endoplasmic reticulum (ER)-mitochondria association and disturbed function of MAM and mitochondria in vitro. These deficits could be rescued by wild-type DJ-1 but not by the familial PD-associated L166P mutant which had demonstrated reduced interaction with IP3R3-Grp75. Furthermore, DJ-1 ablation disturbed calcium efflux-induced IP3R3 degradation after carbachol treatment and caused IP3R3 accumulation at the MAM in vitro. Importantly, similar deficits in IP3R3-Grp75-VDAC1 complexes and MAM were found in the brain of DJ-1 knockout mice in vivo. The DJ-1 level was reduced in the substantia nigra of sporadic PD patients, which was associated with reduced IP3R3-DJ-1 interaction and ER-mitochondria association. Together, these findings offer insights into the cellular mechanism in the involvement of DJ-1 in the regulation of the integrity and calcium cross-talk between ER and mitochondria and suggests that impaired ER-mitochondria association could contribute to the pathogenesis of PD.

scholarly journals A de novo STUB1 variant associated with an early adult-onset multisystemic ataxia phenotype

2021 ◽  
Author(s):  
David Mengel ◽  
Andreas Traschütz ◽  
Selina Reich ◽  
Alejandra Leyva-Gutiérrez ◽  
Friedemann Bender ◽  
...  
Keyword(s):  
Early Onset ◽  
Autosomal Recessive ◽  
Autosomal Dominant ◽  
De Novo ◽  
Family Members ◽  
Start Codon ◽  
Mrna Levels ◽  
Adult Onset ◽  
Loss Of Function ◽  
Autosomal Dominant Disorder

Abstract Background Biallelic STUB1 variants are a well-established cause of autosomal-recessive early-onset multisystemic ataxia (SCAR16). Evidence for STUB1 variants causing autosomal-dominant ataxia (SCA48) so far largely relies on segregation data in larger families. Presenting the first de novo occurrence of a heterozygous STUB1 variant, we here present additional qualitative evidence for STUB1-disease as an autosomal-dominant disorder. Methods Whole exome sequencing on an index patient with sporadic early-onset ataxia, followed by Sanger sequencing in all family members, was used to identify causative variants as well as to rule out alternative genetic hits and intronic STUB1 variants. STUB1 mRNA and protein levels in PBMCs in all family members were analysed using qRT-PCR and Western Blot. Results A previously unreported start-lost loss-of-function variant c.3G>A in the start codon of STUB1 was identified in the index case, occurring de novo and without evidence for a second (potentially missed) variant (e.g., intronic or copy number) in STUB1. The patient showed an early adult-onset multisystemic ataxia complicated by spastic gait disorder, distal myoclonus and cognitive dysfunction, thus closely mirroring the systems affected in autosomal-recessive STUB1-associated disease. In line with the predicted start-lost effect of the variant, functional investigations demonstrated markedly reduced STUB1 protein expression in PBMCs, whereas mRNA levels were intact. Conclusion De novo occurrence of the loss-of-function STUB1 variant in our case with multisystemic ataxia provides a qualitatively additional line of evidence for STUB1-disease as an autosomal-dominant disorder, in which the same neurological systems are affected as in its autosomal-recessive counterpart. Moreover, this finding adds support for loss-of-function as a mechanism underlying autosomal-dominant STUB1-disease, thus mirroring its autosomal-recessive counterpart also in terms of the underlying mutational mechanism.

scholarly journals Deficiency in the autophagy modulator Dram1 exacerbates pyroptotic cell death of Mycobacteria-infected macrophages

2019 ◽  
Author(s):  
Rui Zhang ◽  
Monica Varela ◽  
Gabriel Forn-Cuni ◽  
Vincenzo Torraca ◽  
Michiel van der Vaart ◽  
...  
Keyword(s):  
Cell Death ◽  
Host Resistance ◽  
Transmembrane Protein ◽  
Mycobacterial Infection ◽  
Loss Of Function ◽  
Cellular Functions ◽  
Zebrafish Larvae ◽  
Cell Death Pathways ◽  
New Evidence

AbstractDNA Damage Regulated Autophagy Modulator 1 (DRAM1) is a stress-inducible regulator of autophagy and cell death. DRAM1 has been implicated in cancer, myocardial infarction, and infectious diseases, but the molecular and cellular functions of this transmembrane protein remain poorly understood. Previously, we have proposed DRAM1 as a host resistance factor for tuberculosis (TB) and a potential target for host-directed anti-infective therapies. In this study, we generated a zebrafish dram1 mutant and investigated its loss-of-function effects during Mycobacterium marinum (Mm) infection, a widely used model in TB research. In agreement with previous knockdown analysis, dram1 mutation increased the susceptibility of zebrafish larvae to Mm infection. RNA sequencing revealed major effects of Dram1 deficiency on metabolic, immune response, and cell death pathways during Mm infection, whereas only minor effects on proteinase and metabolic pathways were found under uninfected conditions. Furthermore, unchallenged dram1 mutants did not display overt autophagic defects, but autophagic targeting of Mm was reduced in absence of Dram1. The phagocytic ability of macrophages in dram1 mutants was unaffected, but acidification of Mm-containing vesicles was strongly reduced, indicating that Dram1 is required for phagosome maturation. By in vivo imaging we observed that Dram1-deficient macrophages fail to restrict Mm during early stages of infection. The resulting increase in bacterial burden could be reverted by knockdown of inflammatory caspase a (caspa) and gasdermin Eb (gsdmeb), demonstrating pyroptosis as the mechanism underlying premature cell death of Mm-infected macrophages in dram1 mutants. Collectively, these data demonstrate that dissemination of mycobacterial infection in zebrafish larvae is promoted in absence of Dram1 due to reduced maturation of mycobacteria-containing vesicles, failed intracellular containment, and consequent pyroptotic cell death of infected macrophages. These results provide new evidence that Dram1 plays a central role in host resistance to intracellular infection, acting at the crossroad of autophagy and cell death.

scholarly journals Loss-of-function mutations in FGFR1 cause autosomal dominant Kallmann syndrome

2003 ◽  
Vol 33 (4) ◽  
pp. 463-465 ◽  
Author(s):  
Catherine Dodé ◽  
Jacqueline Levilliers ◽  
Jean-Michel Dupont ◽  
Anne De Paepe ◽  
Nathalie Le Dû ◽  
...  
Keyword(s):  
Autosomal Dominant ◽  
Kallmann Syndrome ◽  
Loss Of Function

scholarly journals Proteins linked to autosomal dominant and autosomal recessive disorders harbor characteristic rare missense mutation distribution patterns

2015 ◽  
Author(s):  
Tychele Turner ◽  
Christopher Douville ◽  
Dewey Kim ◽  
Peter D Stenson ◽  
David N Cooper ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Autosomal Recessive ◽  
Autosomal Dominant ◽  
Distribution Patterns ◽  
Missense Mutations ◽  
Loss Of Function ◽  
Gain Of Function ◽  
Disease Etiology ◽  
Missense Variants ◽  
Significant Difference

The role of rare missense variants in disease causation remains difficult to interpret. We explore whether the clustering pattern of rare missense variants (MAF<0.01) in a protein is associated with mode of inheritance. Mutations in genes associated with autosomal dominant (AD) conditions are known to result in either loss or gain of function, whereas mutations in genes associated with autosomal recessive (AR) conditions invariably result in loss of function. Loss- of-function mutations tend to be distributed uniformly along protein sequence, while gain-of- function mutations tend to localize to key regions. It has not previously been ascertained whether these patterns hold in general for rare missense mutations. We consider the extent to which rare missense variants are located within annotated protein domains and whether they form clusters, using a new unbiased method called CLUstering by Mutation Position (CLUMP). These approaches quantified a significant difference in clustering between AD and AR diseases. Proteins linked to AD diseases exhibited more clustering of rare missense mutations than those linked to AR diseases (Wilcoxon P=5.7x10-4, permutation P=8.4x10-4). Rare missense mutation in proteins linked to either AD or AR diseases were more clustered than controls (1000G) (Wilcoxon P=2.8x10-15 for AD and P=4.5x10-4 for AR, permutation P=3.1x10-12 for AD and P=0.03 for AR). Differences in clustering patterns persisted even after removal of the most prominent genes. Testing for such non-random patterns may reveal novel aspects of disease etiology in large sample studies.

scholarly journals SAT-LB071 Loss of Function (LoF) mutations in TCF12 Cause Autosomal Dominant Kallmann Syndrome and Reveal Network-level Interactions Between Causal Loci

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
David Keefe ◽  
Ravikumar Balasubramanian ◽  
Erica Davis ◽  
Zachary Kupchinsky ◽  
Lacey Plummer ◽  
...  
Keyword(s):  
Autosomal Dominant ◽  
Kallmann Syndrome ◽  
Loss Of Function

Nail-Patella Syndrome

2015 ◽  
Vol 19 (6) ◽  
pp. 595-599 ◽  
Author(s):  
Najla Al-Dawsari ◽  
Ahmed Al-Mokhadam ◽  
Hind Al-Abdulwahed ◽  
Nouriya Al-Sannaa
Keyword(s):  
Autosomal Recessive ◽  
Autosomal Dominant ◽  
Anterior Segment ◽  
Heterozygous Mutation ◽  
Loss Of Function ◽  
Consanguineous Family ◽  
Autosomal Dominant Disorder ◽  
Nail Changes ◽  
Chromosome 9Q ◽  
Nail Patella Syndrome

Background: Nail-patella syndrome (NPS) is an autosomal dominant disorder with a variable interfamilial and intrafamilial clinical expressivity and penetrance. It is caused by loss-of-function heterozygous mutation in the LIM-homeodomain transcription factor (LMX1B) located on chromosome 9q. The pleiotropic LMB1X gene, a member of the homeogene family, is involved in the development of glomerular basement membrane, dorsoventral limb structures, along with the nails and the anterior segment of the eye. Objective: Here, we report a Saudi Arab consanguineous family with 2 affected sisters presented with the typical nail changes of NPS. Methods: DNA samples were collected from the sisters and their parents after consent. Results: Both sisters were found to be homozygous for a previously described disease-causing mutation (c.268C>T) at the (LMX1B) gene. Both of the phenotypically normal parents were confirmed to be heterozygous for the same mutation. Conclusion: This finding supports the autosomal recessive mode of inheritance in this family.

The Kallmann syndrome gene homolog in C. elegans is involved in epidermal morphogenesis and neurite branching

Development ◽  
2002 ◽  
Vol 129 (5) ◽  
pp. 1283-1294
Author(s):  
Elena I. Rugarli ◽  
Elia Di Schiavi ◽  
Massimo A. Hilliard ◽  
Salvatore Arbucci ◽  
Cristina Ghezzi ◽  
...  
Keyword(s):  
Mouse Model ◽  
Axon Guidance ◽  
Neurite Outgrowth ◽  
Kallmann Syndrome ◽  
Gonadotropin Releasing Hormone ◽  
Secreted Protein ◽  
C Elegans ◽  
Functional Conservation ◽  
And Migration

Kallmann syndrome is an inherited disorder defined by the association of anosmia and hypogonadism, owing to impaired targeting and migration of olfactory axons and gonadotropin-releasing hormone secreting neurons. The gene responsible for the X-linked form of Kallmann syndrome, KAL-1, encodes a secreted protein of still elusive function. It has been proposed that KAL-1 might be involved in some aspects of olfactory axon guidance. However, the unavailability of a mouse model, and the difficulties in studying cellular and axonal migration in vertebrates have hampered an understanding of its function. We have identified the C. elegans homolog, kal-1, and document its function in vivo. We show that kal-1 is part of a mechanism by which neurons influence migration and adhesion of epidermal cells undergoing morphogenesis during ventral enclosure and male tail formation. We also show that kal-1 affects neurite outgrowth in vivo by modulating branching. Finally, we find that human KAL-1 cDNA can compensate for the loss of worm kal-1 and that overexpression of worm or human KAL-1 cDNAs in the nematode results in the same phenotypes. These data indicate functional conservation between the human and nematode proteins and establish C. elegans as a powerful animal in which to investigate KAL function in vivo. Our findings add a new player to the set of molecules, which appear to underlie both morphogenesis and axonal/neuronal navigation in vertebrates and invertebrates.

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