Darius Ebrahimi-Fakhari

Darius Ebrahimi-Fakhari
Boston Children's Hospital ·  Department of Neurology

MD, PhD

About

120
Publications
79,890
Reads
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7,996
Citations
Citations since 2016
79 Research Items
7543 Citations
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201620172018201920202021202202004006008001,0001,2001,400
201620172018201920202021202202004006008001,0001,2001,400
Introduction
Dr. Ebrahimi-Fakhari’s research interests cover childhood-onset neurogenetic, neurodegenerative, and movement disorders. He leads a translational research program that aims to discover novel therapies for childhood-onset forms of hereditary spastic paraplegia and disorders related to the autophagy pathway. Current work covers gene discovery, natural history studies, disease modeling in iPSC-derived neurons and zebrafish, and high-throughput small molecule screens and CRISPR screens.
Additional affiliations
April 2014 - December 2021
Boston Children's Hospital
Position
  • Researcher
April 2013 - April 2014
University Hospital Heidelberg
Position
  • Pediatrician
Education
October 2006 - April 2013
Universität Heidelberg
Field of study
  • Medicine

Publications

Publications (120)
Article
Full-text available
CAPN1‐associated hereditary spastic paraplegia (SPG76) is a rare and clinically heterogenous syndrome due to loss of calpain‐1 function. Here we illustrate a translational approach to the case of an 18‐year‐old patient who first presented with psychiatric symptoms followed by spastic gait, intention tremor, and neurogenic bladder dysfunction, consi...
Article
Childhood‐onset forms of hereditary spastic paraplegia are ultra‐rare diseases and often present with complex features. Next‐generation‐sequencing allows for an accurate diagnosis in many cases but the interpretation of novel variants remains challenging, particularly for missense mutations. Where sufficient knowledge of the protein function and/or...
Article
Pathogenic variants in ATL1 are a known cause of autosomal-dominantly inherited hereditary spastic paraplegia (HSP-ATL1, SPG3A) with a predominantly ‘pure’ HSP phenotype. Although a relatively large number of patients have been reported, no genotype-phenotype correlations have been established for specific ATL1 variants. Confronted with five childr...
Article
Bi‐allelic loss‐of‐function variants in Von Willebrand factor type A (VWA1) were recently discovered to lead to an early onset motor neuropathy or neuromyopathy. What makes this discovery particularly notable is the high frequency of one of the VWA1 (NM_022834.5) founder variants, c.62_71dup (p.Gly25ArgfsTer74), which nears 0.01% in European popula...
Article
Background: Familial hereditary spastic paraplegia (HSP)-SPAST (SPG4) typically presents with a pure HSP phenotype. Objective: The aim of this study was to delineate the genotypic and phenotypic spectrum of children with de novo HSP-SPAST. Methods: This study used a systematic cross-sectional analysis of clinical and molecular features. Resul...
Article
In the field of hereditary spastic paraplegia (HSP), progress in molecular diagnostics needs to be translated into robust phenotyping studies to understand genetic and phenotypic heterogeneity and to support interventional trials. ZFYVE26-associated hereditary spastic paraplegia (HSP-ZFYVE26, SPG15) is a rare, early-onset complex HSP, characterized...
Article
Full-text available
Clinical characteristics - With the current widespread use of multigene panels and comprehensive genomic testing, it has become apparent that the phenotypic spectrum of EPG5-related disorder represents a continuum. At the most severe end of the spectrum is classic Vici syndrome (defined as a neurodevelopmental disorder with multisystem involvement...
Article
Pathogenic variants in ATL1 are a known cause of autosomal-dominantly inherited hereditary spastic paraplegia (HSP-ATL1, SPG3A) with a predominantly ‘pure’ HSP phenotype. Although a relatively large number of patients have been reported, no genotype–phenotype correlations have been established for specific ATL1 variants. Confronted with five childr...
Article
Full-text available
In 2016, the Movement Disorder Society Task Force for the Nomenclature of Genetic Movement Disorders presented a new system for naming genetically determined movement disorders and provided a criterion-based list of confirmed monogenic movement disorders. Since then, a substantial number of novel disease-causing genes have been described, which war...
Article
Full-text available
Mutations in the SCN8A gene encoding the voltage-gated sodium channel α-subunit Nav1. 6 have been reported in individuals with epilepsy, intellectual disability and features of autism spectrum disorder. SCN8A is widely expressed in the central nervous system, including the cerebellum. Cerebellar dysfunction has been implicated in autism spectrum di...
Article
Full-text available
The adaptor protein complex AP-4 mediates anterograde axonal transport and is essential for axon health. AP-4-deficient patients suffer from a severe neurodevelopmental and neurodegenerative disorder. Here we identify DAGLB (diacylglycerol lipase-beta), a key enzyme for generation of the endocannabinoid 2-AG (2-arachidonoylglycerol), as a cargo of...
Article
Full-text available
Objectives: Cerebral palsy (CP) is the most common childhood motor disability, yet its link to single-gene disorders is under-characterized. To explore the genetic landscape of CP, we conducted whole exome sequencing (WES) in a cohort of patients with CP. Methods: We performed comprehensive phenotyping and WES on a prospective cohort of individu...
Article
WDR45-related neurodevelopmental disorder (NDD) is a clinically-heterogenous congenital disorder of macroautophagy/autophagy. The natural history of this ultra-orphan disease remains incompletely understood, leading to delays in diagnosis and lack of quantifiable outcome measures. In this cross-sectional study, we model quantitative natural history...
Poster
The hereditary spastic paraplegias (HSP) are a group of over 80 different neurogenetic disorders and the most common cause of inherited spasticity and associated disability. Childhood-onset forms of HSP often pose a diagnostic challenge given their non-specific clinical presentation and slow progression in many cases. Next generation sequencing has...
Article
Full-text available
Adaptor protein complex 4 (AP-4)-associated hereditary spastic paraplegia is caused by biallelic loss-of-function variants in AP4B1, AP4M1, AP4E1 or AP4S1, which constitute the four subunits of this obligate complex. While the diagnosis of AP-4-associated hereditary spastic paraplegia relies on molecular testing, the interpretation of novel missens...
Article
Full-text available
Background and Objectives AP-4-associated hereditary spastic paraplegia (AP-4-HSP: SPG47, SPG50, SPG51, SPG52) is an emerging cause of childhood-onset hereditary spastic paraplegia and mimic of cerebral palsy. This study aims to define the spectrum of brain MRI findings in AP-4-HSP and to investigate radio-clinical correlations. Methods A systemat...
Article
Full-text available
WIPI2 is a member of the human WIPI protein family (seven-bladed b-propeller proteins binding phosphatidylinositols, PROPPINs), which play a pivotal role in autophagy and has been implicated in the pathogenesis of several neurological conditions. The homozygous WIPI2 variant c.745G>A; p.(Val249Met) (NM_015610.4) has recently been associated with a...
Article
Full-text available
Objective: AP-4-associated hereditary spastic paraplegia (AP-4-HSP) is a childhood-onset neurogenetic disease and mimic of cerebral palsy. Data on health-related quality of life (HRQoL) are lacking. To establish a metric for HRQoL and caregiver priorities, we used the Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD)...
Article
Early-onset forms of hereditary spastic paraplegia and inborn errors of metabolism that present with spastic diplegia are among the most common "mimics" of cerebral palsy. Early detection of these heterogenous genetic disorders can inform genetic counseling, anticipatory guidance, and improve outcomes, particularly where specific treatments exist....
Article
Full-text available
Summary Clinical characteristics. Spastic paraplegia 15 (SPG15), typically an early-onset complex hereditary spastic paraplegia, is characterized by progressive spasticity that begins in the lower extremities and is associated with several manifestations resulting from central and peripheral nervous system dysfunction. While onset of spasticity is...
Article
Full-text available
Bi‐allelic TECPR2 variants have been associated with a complex syndrome with features of both a neurodevelopmental and neurodegenerative disorder. Here, we provide a comprehensive clinical description and variant interpretation framework for this genetic locus. Through an international collaboration, we identified 17 individuals from 15 families wi...
Article
Full-text available
Biallelic loss-of-function variants in the subunits of the adaptor protein complex 4 lead to childhood-onset hereditary spastic paraplegia (AP-4-HSP): SPG47 (AP4B1), SPG50 (AP4M1), SPG51 (AP4E1), and SPG52 (AP4S1). Here, we describe the generation of induced pluripotent stem cells (iPSCs) from three AP-4-HSP patients with biallelic, loss-of-functio...
Article
Full-text available
In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monit...
Preprint
Full-text available
In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monit...
Preprint
Full-text available
the PDF can be download freely on pubmed. https://pubmed.ncbi.nlm.nih.gov/33634751/
Cover Page
Full-text available
In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monit...
Article
Full-text available
In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monit...
Article
Full-text available
Objective Uniparental isodisomy can lead to blended phenotypes of imprinting disorders and autosomal recessive diseases. To determine whether a complex neurodevelopmental disorder was caused by uniparental isodisomy, a detailed clinical and molecular characterization was performed. Methods A combination of clinical, molecular, and imaging data and...
Book
Book description Inherited metabolic movement disorders are a significant and rapidly evolving field of study, linking two subspecialty areas of childhood-onset movement disorders and inborn errors of metabolism. Increasing the chance of early recognition of inherited metabolic movement disorders can have significant therapeutic implications for pa...
Preprint
The adaptor protein complex AP-4 mediates anterograde axonal transport and is essential for axon health. AP-4-deficient patients suffer from a severe neurological disorder, which encompasses neurodevelopmental and neurodegenerative features. While impaired autophagy has been suggested to account for axon degeneration in AP-4 deficiency, axon growth...
Preprint
Full-text available
PURPOSE Bi-allelic TECPR2 variants have been associated with a complex syndrome with features of both a neurodevelopmental and neurodegenerative disorder. Here, we aim to provide a comprehensive clinical description and variant interpretation framework. METHODS Through an international collaboration, we identified 13 individuals from 12 families w...
Article
Bi-allelic loss-of-function variants in genes that encode subunits of the adaptor protein complex 4 (AP-4) lead to prototypical yet poorly understood forms of childhood-onset and complex hereditary spastic paraplegia: SPG47 (AP4B1), SPG50 (AP4M1), SPG51 (AP4E1) and SPG52 (AP4S1). Here, we report a detailed cross-sectional analysis of clinical, imag...
Article
Full-text available
Bi-allelic loss-of-function variants in genes that encode subunits of the adaptor protein complex 4 (AP-4) lead to prototypical yet poorly understood forms of childhood-onset and complex hereditary spastic paraplegia: SPG47 (AP4B1), SPG50 (AP4M1), SPG51 (AP4E1) and SPG52 (AP4S1). Here, we report a detailed cross-sectional analysis of clinical, imag...
Article
Full-text available
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
Full-text available
Autosomal recessive spastic paraplegia 52 is caused by biallelic mutations in AP4S1 which encodes a subunit of the adaptor protein complex 4 (AP‐4). Using next‐generation sequencing, we identified three novel unrelated SPG52 patients from a cohort of patients with cerebral palsy. The discovered variants in AP4S1 lead to reduced AP‐4 complex formati...
Article
Full-text available
ERLIN2‐related disorders are rare conditions of the motor system and clinical details are limited to a small number of prior descriptions. We here presented clinical and genetic details in five individuals (four different families) where three subjects carried a common homozygous p.Asn292ArgfsX26, associated also with sensorineural hearing loss in...
Article
Deficiency of the adaptor protein complex 4 (AP-4) leads to childhood-onset hereditary spastic paraplegia (AP-4-HSP): SPG47 (AP4B1), SPG50 (AP4M1), SPG51 (AP4E1) and SPG52 (AP4S1). This study aims to evaluate the impact of loss-of-function variants in AP-4 subunits on intracellular protein trafficking using patient-derived cells. We investigated 15...
Conference Paper
Succinic semialdehyde dehydrogenase deficiency (SSADHD) represents a rare monogenetic, autosomal-recessive disorder causing an enzymatic block of the degradation of gamma-aminobutyric acid (GABA) due to variants in ALDH5A1. Succinic semialdehyde cannot be converted to succinate and is consecutively converted to gamma-hydroxybutyrate (GHB). The phen...
Article
Full-text available
Bi-allelic variants in the subunits of the adaptor protein complex 4 lead to childhood-onset, complex hereditary spastic paraplegia (AP-4-HSP): SPG47 (AP4B1), SPG50 (AP4M1), SPG51 (AP4E1), and SPG52 (AP4S1). Here, we describe the generation of induced pluripotent stem cells (iPSCs) from three AP-4-HSP patients with compound-heterozygous, loss-of-fu...
Article
Aim To assess the role of the TAND (tuberous sclerosis complex [TSC] associated neuropsychiatric disorders) checklist as a screening tool for neuropsychiatric pathology, to evaluate behavioral and psychiatric symptoms and related parental stress in children with TSC, and to analyze associations between parental stress, TAND findings, and TSC pathol...
Article
Congenital disorders of autophagy are multisystem disorders with significant neurological involvement. Ectopic p-granules protein 5 (EPG5)-associated Vici syndrome is a prototypical congenital disorder of autophagy and presents with the cardinal features of agenesis of the corpus callosum, cataracts, cardiomyopathy, immunodeficiency, and oculocutan...
Conference Paper
Succinic semialdehyde dehydrogenase deficiency (SSADHD) is an autosomal- recessive disorder caused by variants of the ALDH5A1 gene. Symptoms include developmental delay, behavioral problems, impaired motor coordination and seizures. High concentrations of the neurotransmitter gamma-amino butyric acid (GABA) and its degradation byproduct gamma-hydro...
Article
Autophagy is a fundamental and conserved catabolic pathway that mediates the degradation of macromolecules and organelles in lysosomes. Autophagy is particularly important to post‐mitotic and metabolically active cells such as neurons. The complex architecture of neurons and their long axons pose additional challenges for efficient recycling of car...
Article
There are several hundred single‐gene disorders that we classify as inborn errors of metabolism. Inborn errors of metabolism are often rare and highly heterogeneous multisystem diseases with non‐neurological and neurological manifestations, commonly with onset during childhood. Movement disorders are among the most common neurological problems in i...
Article
Full-text available
Summary Clinical characteristics. AP-4-associated hereditary spastic paraplegia (HSP), also known as AP-4 deficiency syndrome, is a group of neurodegenerative disorders characterized by a progressive, complex spastic paraplegia with onset typically in infancy or early childhood. Early-onset hypotonia evolves into progressive lower-extremity spastic...
Article
Full-text available
Background: Tuberous Sclerosis Complex (TSC) is a rare multisystem disorder. In 2012 diagnostic criteria for TSC were revised. However, data on the incidence of TSC are limited. Methods: Prospective, national surveillance study in Germany over a 2-year-period (03/2015-02/2017) using current revised criteria for TSC. Patients up to the age of 18...
Article
The mechanistic target of rapamycin (mTOR) is an important signaling hub that integrates environmental information regarding energy availability and stimulates anabolic molecular processes and cell growth. Abnormalities in this pathway have been identified in several syndromes in which autism spectrum disorder (ASD) is highly prevalent. Several stu...
Article
Full-text available
A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.
Article
Full-text available
Dysregulated miRNA expression and mutation of genes involved in miRNA biogenesis have been reported in motor neuron diseases including spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS). Therefore, identifying molecular mechanisms governing miRNA expression is important to understand these diseases. Here, we report that expressio...
Article
Full-text available
Summary Clinical characteristics. PRRT2-associated paroxysmal movement disorders (PRRT2-PxMD) include paroxysmal kinesigenic dyskinesia (PKD), benign familial infantile epilepsy (BFIE), paroxysmal kinesigenic dyskinesia with infantile convulsions (PKD/IC), and hemiplegic migraine (HM). In addition, PRRT2 pathogenic variants have been identified in...
Article
Full-text available
Background: Movement disorders are a significant clinical problem in lysosomal storage diseases (LSD) and account for substantial morbidity. The spectrum of movement disorders in childhood-onset LSD, however, remains poorly defined. Objectives: To define the spectrum of movement disorders in a well-characterized cohort of children with LSD. Met...
Article
Autophagy is a fundamental and conserved intracellular pathway that mediates the degradation of macromolecules and organelles in lysosomes. Proper autophagy function is important for central nervous system development and neuronal function. Over the last 5 years, several single gene disorders of the autophagy pathway have emerged: EPG5-associated V...
Article
Full-text available
The hereditary spastic paraplegias (HSPs) are a heterogeneous group of disorders characterized by degeneration of the corticospinal and spinocerebellar tracts leading to progressive spasticity. One subtype, spastic paraplegia type 47 (SPG47 or HSP-AP4B1), is due to bi-allelic loss-of-function mutations in the AP4B1 gene. AP4B1 is a subunit of the a...
Article
p62/sequestosome-1 (SQSTM1) is a multifunctional adaptor protein and autophagic substrate which accumulates in cells with hyperactive mTORC1, such as kidney cells with mutations in the tumor suppressor genes TSC1 or TSC2. Here we report that p62 is a critical mediator of TSC2-driven tumorigenesis, as Tsc2+/- and Tsc2f/f Ksp-CreERT2+ mice crossed to...
Article
Lysosomal storage diseases (LSD) are inborn errors of metabolism resulting in multisystem disease. Central nervous system involvement, often with progressive neurodegeneration, accounts for a large portion of the morbidity and mortality seen in many LSD. Available treatments fail to prevent or correct neurologic symptoms and decline. Emerging evide...