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result(s) for
"Muscle Hypotonia - diagnosis"
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Changing facial phenotype in Cohen syndrome: towards clues for an earlier diagnosis
by
Blair, Edward
,
Masurel-Paulet, Alice
,
Rump, Patrick
in
Abnormalities, Multiple
,
Aging
,
Auricle
2013
Cohen syndrome (CS) is a rare autosomal recessive condition caused by mutations and/or large rearrangements in the VPS13B gene. CS clinical features, including developmental delay, the typical facial gestalt, chorioretinal dystrophy (CRD) and neutropenia, are well described. CS diagnosis is generally raised after school age, when visual disturbances lead to CRD diagnosis and to VPS13B gene testing. This relatively late diagnosis precludes accurate genetic counselling. The aim of this study was to analyse the evolution of CS facial features in the early period of life, particularly before school age (6 years), to find clues for an earlier diagnosis. Photographs of 17 patients with molecularly confirmed CS were analysed, from birth to preschool age. By comparing their facial phenotype when growing, we show that there are no special facial characteristics before 1 year. However, between 2 and 6 years, CS children already share common facial features such as a short neck, a square face with micrognathia and full cheeks, a hypotonic facial appearance, epicanthic folds, long ears with an everted upper part of the auricle and/or a prominent lobe, a relatively short philtrum, a small and open mouth with downturned corners, a thick lower lip and abnormal eye shapes. These early transient facial features evolve to typical CS facial features with aging. These observations emphasize the importance of ophthalmological tests and neutrophil count in children in preschool age presenting with developmental delay, hypotonia and the facial features we described here, for an earlier CS diagnosis.
Journal Article
Variants in GNAI1 cause a syndrome associated with variable features including developmental delay, seizures, and hypotonia
by
Powell, Corinna
,
van Jaarsveld, Richard H.
,
Monaghan, Kristin G.
in
Biomedical and Life Sciences
,
Biomedicine
,
Child
2021
Purpose
Neurodevelopmental disorders (NDDs) encompass a spectrum of genetically heterogeneous disorders with features that commonly include developmental delay, intellectual disability, and autism spectrum disorders. We sought to delineate the molecular and phenotypic spectrum of a novel neurodevelopmental disorder caused by variants in the
GNAI1
gene.
Methods
Through large cohort trio-based exome sequencing and international data-sharing, we identified 24 unrelated individuals with NDD phenotypes and a variant in
GNAI1
, which encodes the inhibitory Gαi1 subunit of heterotrimeric G-proteins. We collected detailed genotype and phenotype information for each affected individual.
Results
We identified 16 unique variants in
GNAI1
in 24 affected individuals; 23 occurred de novo and 1 was inherited from a mosaic parent. Most affected individuals have a severe neurodevelopmental disorder. Core features include global developmental delay, intellectual disability, hypotonia, and epilepsy.
Conclusion
This collaboration establishes
GNAI1
variants as a cause of NDDs.
GNAI1
-related NDD is most often characterized by severe to profound delays, hypotonia, epilepsy that ranges from self-limiting to intractable, behavior problems, and variable mild dysmorphic features.
Journal Article
Automatic analysis of muscular activity in the flexor digitorum superficialis muscles: a fast screening method for rapid eye movement sleep without atonia
by
Gaig, Carles
,
Högl, Birgit
,
Santamaria, Joan
in
Chief financial officers
,
Electromyography - methods
,
Eye movements
2023
Abstract
Study objectives
To identify a fast and reliable method for rapid eye movement (REM) sleep without atonia (RWA) quantification.
Methods
We analyzed 36 video-polysomnographies (v-PSGs) of isolated REM sleep behavior disorder (iRBD) patients and 35 controls’ v-PSGs. Patients diagnosed with RBD had: i) RWA, quantified with a reference method, i.e. automatic and artifact-corrected 3-s Sleep Innsbruck Barcelona (SINBAR) index in REM sleep periods (RSPs, i.e. manually selected portions of REM sleep); and ii) v-PSG-documented RBD behaviors. We quantified RWA with other (semi)-automated methods requiring less human intervention than the reference one: the indices proposed by the SINBAR group (the 3-s and 30-s phasic flexor digitorum superficialis (FDS), phasic/”any”/tonic mentalis), and the REM atonia, short and long muscle activity indices (in mentalis/submentalis/FDS muscles). They were calculated in whole REM sleep (i.e. REM sleep scored following international guidelines), in RSPs, with and without manual artifact correction. Area under curves (AUC) discriminating iRBD from controls were computed. Using published cut-offs, the indices’ sensitivity and specificity for iRBD identification were calculated. Apnea-hypopnea index in REM sleep (AHIREM) was considered in the analyses.
Results
RWA indices from FDS muscles alone had the highest AUCs and all of them had 100% sensitivity. Without manual RSP selection and artifact correction, the “30-s phasic FDS” and the “FDS long muscle activity” had the highest specificity (85%) with AHIREM < 15/h. RWA indices were less reliable when AHIREM≥15/h.
Conclusions
If AHIREM<15/h, FDS muscular activity in whole REM sleep and without artifact correction is fast and reliable to rule out RWA.
Journal Article
Normative and isolated rapid eye movement sleep without atonia in adults without REM sleep behavior disorder
2019
Values for normative REM sleep without atonia (RSWA) remain unclear. Older age and male sex are associated with greater RSWA, and isolated elevated RSWA has been reported. We aimed to describe normative RSWA and characterize isolated RSWA frequency in adults without REM sleep behavior disorder (RBD).
We visually quantified phasic, \"any,\" and tonic RSWA in the submentalis (SM) and anterior tibialis (AT) muscles, and the automated Ferri REM Atonia Index during polysomnography in adults without RBD aged 21-88. We calculated RSWA percentiles across age and sex deciles and compared RSWA in older (≥ 65) versus younger (<65) men and women. Isolated RSWA (exceeding diagnostic RBD cutoffs, or >95th percentile) frequency was also determined.
Overall, 95th percentile RSWA percentages were SM phasic, any, tonic = 8.6%, 9.1%, 0.99%; AT phasic and \"any\" = 17.0%; combined SM/AT phasic, \"any\" = 22.3%, 25.5%; and RAI = 0.85. Most phasic RSWA burst durations were ≤1.0 s (85th percentiles: SM = 1.07, AT = 0.86 seconds). Older men had significantly higher AT RSWA than older women and younger patients (all p < 0.04). Twenty-nine (25%, 18 men) had RSWA exceeding the cohort 95th percentile, while 17 (14%, 12 men) fulfilled diagnostic cutoffs for phasic or automated RBD RSWA thresholds.
RSWA levels are highest in older men, mirroring the demographic characteristics of RBD, suggesting that older men frequently have altered REM sleep atonia control. These data establish normative adult RSWA values and thresholds for determination of isolated RSWA elevation, potentially aiding RBD diagnosis and discussions concerning incidental RSWA in clinical sleep medicine practice.
Journal Article
Heterozygous HNRNPU variants cause early onset epilepsy and severe intellectual disability
by
Kuechler, Alma
,
Wollnik, Bernd
,
Bramswig, Nuria C.
in
Age of Onset
,
Agenesis of Corpus Callosum - genetics
,
Biomedical and Life Sciences
2017
Pathogenic variants in genes encoding subunits of the spliceosome are the cause of several human diseases, such as neurodegenerative diseases. The RNA splicing process is facilitated by the spliceosome, a large RNA–protein complex consisting of small nuclear ribonucleoproteins (snRNPs), and many other proteins, such as heterogeneous nuclear ribonucleoproteins (hnRNPs). The
HNRNPU
gene (OMIM *602869) encodes the heterogeneous nuclear ribonucleoprotein U, which plays a crucial role in mammalian development.
HNRNPU
is expressed in the fetal brain and adult heart, kidney, liver, brain, and cerebellum. Microdeletions in the 1q44 region encompassing
HNRNPU
have been described in patients with intellectual disability (ID) and other clinical features, such as seizures, corpus callosum abnormalities (CCA), and microcephaly. Recently, pathogenic
HNRNPU
variants were identified in large ID and epileptic encephalopathy cohorts. In this study, we provide detailed clinical information of five novels and review two of the previously published individuals with (likely) pathogenic
de novo
variants in the
HNRNPU
gene including three non-sense and two missense variants, one small intragenic deletion, and one duplication. The phenotype in individuals with variants in
HNRNPU
is characterized by early onset seizures (6/7), severe ID (6/6), severe speech impairment (6/6), hypotonia (6/7), and central nervous system (CNS) (5/6), cardiac (4/6), and renal abnormalities (3/4). In this study, we broaden the clinical and mutational
HNRNPU
-associated spectrum, and demonstrate that heterozygous
HNRNPU
variants cause epilepsy, severe ID with striking speech impairment and variable CNS, cardiac, and renal anomalies.
Journal Article
Altered Behavioral Performance and Live Imaging of Circuit-Specific Neural Deficiencies in a Zebrafish Model for Psychomotor Retardation
by
Appelbaum, Lior
,
Tovin, Adi
,
Lerer-Goldshtein, Tali
in
Analysis
,
Animals
,
Animals, Genetically Modified
2014
The mechanisms and treatment of psychomotor retardation, which includes motor and cognitive impairment, are indefinite. The Allan-Herndon-Dudley syndrome (AHDS) is an X-linked psychomotor retardation characterized by delayed development, severe intellectual disability, muscle hypotonia, and spastic paraplegia, in combination with disturbed thyroid hormone (TH) parameters. AHDS has been associated with mutations in the monocarboxylate transporter 8 (mct8/slc16a2) gene, which is a TH transporter. In order to determine the pathophysiological mechanisms of AHDS, MCT8 knockout mice were intensively studied. Although these mice faithfully replicated the abnormal serum TH levels, they failed to exhibit the neurological and behavioral symptoms of AHDS patients. Here, we generated an mct8 mutant (mct8-/-) zebrafish using zinc-finger nuclease (ZFN)-mediated targeted gene editing system. The elimination of MCT8 decreased the expression levels of TH receptors; however, it did not affect the expression of other TH-related genes. Similar to human patients, mct8-/- larvae exhibited neurological and behavioral deficiencies. High-throughput behavioral assays demonstrated that mct8-/- larvae exhibited reduced locomotor activity, altered response to external light and dark transitions and an increase in sleep time. These deficiencies in behavioral performance were associated with altered expression of myelin-related genes and neuron-specific deficiencies in circuit formation. Time-lapse imaging of single-axon arbors and synapses in live mct8-/- larvae revealed a reduction in filopodia dynamics and axon branching in sensory neurons and decreased synaptic density in motor neurons. These phenotypes enable assessment of the therapeutic potential of three TH analogs that can enter the cells in the absence of MCT8. The TH analogs restored the myelin and axon outgrowth deficiencies in mct8-/- larvae. These findings suggest a mechanism by which MCT8 regulates neural circuit assembly, ultimately mediating sensory and motor control of behavioral performance. We also propose that the administration of TH analogs early during embryo development can specifically reduce neurological damage in AHDS patients.
Journal Article
Clinical and molecular spectrum along with genotype–phenotype correlation of 25 patients diagnosed with 3 M syndrome: a study from Turkey
by
Elcioglu, Nursel H.
,
Kolbaşı, Barış
,
Ünal, Edip
in
Birth weight
,
Bone dysplasia
,
Carrier Proteins
2024
3 M syndrome is a well-known autosomal recessive skeletal genetic disorder caused by biallelic pathogenic variants in the
CUL7
,
OBSL1
, and
CCDC8
genes. Affected individuals exhibit profound pre- and postnatal growth retardation, distinctive facial features with normal intelligence. This study aims to provide insight into the comprehensive evaluation of clinical, laboratory, and radiological findings, expand the mutational spectrum of the disease, and establish a genotype–phenotype correlation in the present cases. A total of 25 patients from 19 unrelated families were included in the study. Genetic etiology was determined in probands through the utilization of Sanger sequencing and/or targeted gene panel analysis. The clinical, laboratory, and genetic features of all patients at admission and during follow-up were documented. Genotype–phenotype correlation was carried out in the CUL7 and OBSL1 groups. The genetic etiology was established in all patients (
n
= 25/25, 100%). We identified 15 distinct variants in
CUL7
,
OBSL1
, and
CCDC8
genes, with eleven being novel.
CUL7
variants were present in 13 patients (
n
= 13/25, 52%), while
OBSL1
variants were found in 11 patients (
n
= 11/25, 44%). No notable distinctions were found in mean birth weight, height, and standard deviation scores between the
CUL7
and
OBSL1
mutation groups (
p
> 0.05). Patients with
CUL7
variants exhibited significantly lower height standard deviation scores both at admission and at the last examination, as well as lower weight standard deviation scores at the last examination, compared to those with
OBSL1
variants (
p
< 0.05).
Conclusion
: To date, genotype–phenotype correlations have been identified in a limited number of studies. Further research involving larger cohorts is necessary to solidify these correlations.
What is Known:
•
3M syndrome is a well-known skeletal dysplasia caused by biallelic pathogenic variants in CUL7, OBSL1, and CCDC8 genes
.
•
Despite genetic heterogeneity, clinical, and radiologic features show homogeneity in affected individuals
.
What is New:
•
Genotype-phenotype correlations have been established in limited studies
.
•
The CUL7 group exhibited significantly lower height SDS at both admission and the final evaluation and lower weight SDS at the final examination compared to the OBSL1 group
.
•
The frequency of variants in the OBSL1 gene among Turkish patients exceeds the rates reported in the literature
.
•
Gradenigo syndrome is being reported for the first time in a patient with 3M syndrome
.
Journal Article
Multiple problems: a case of Cohen syndrome VPS13B mutation causing bilateral spherical lenses combined with retinitis pigmentosa
2025
Background
Cohen syndrome is a rare autosomal recessive disorder characterized by facial anomalies with or without microcephaly, non-progressive intellectual disability, hypotonia, ocular abnormalities, and neutropenia. Due to its low prevalence and diverse presentations, much information about the disease, including ocular manifestations, is not yet fully understood. To date, there is a paucity of literature on Cohen syndrome, which is characterized by predominantly ocular manifestations and typical manifestations in multiple systems throughout the body.
Case presentation
A 24-year-old male with a history of intellectual disability since childhood presented with decreased vision in both eyes for 2 years. He was diagnosed with bilateral spherical lens, bilateral subluxation of lens, bilateral concurrent cataracts, and bilateral retinitis pigmentosa. Cataract extraction combined with intraocular lens implantation was successful in both eyes, and vision improved after surgery. His underlying syndrome was studied genetically by whole exome sequencing. Genetic testing through whole-exome sequencing revealed a mutation in the VPS13B gene: c.6865 + 1G > T, confirming the diagnosis of Cohen syndrome.
Conclusion
Ophthalmologists should consider the diagnosis of Cohen syndrome in patients with developmental delay, spherical lens, and retinitis pigmentosa. A detailed ophthalmologic examination and general examination should be considered in such patients.
Journal Article
PITX2 and FOXC1 spectrum of mutations in ocular syndromes
by
Broeckel, Ulrich
,
Volkmann Kloss, Bethany A
,
Zwijnenburg, Petra J G
in
Alleles
,
Anterior Eye Segment - abnormalities
,
Biological and medical sciences
2012
Anterior segment dysgenesis (ASD) encompasses a broad spectrum of developmental conditions affecting anterior ocular structures and associated with an increased risk for glaucoma. Various systemic anomalies are often observed in ASD conditions such as Axenfeld-Rieger syndrome (ARS) and De Hauwere syndrome. We report DNA sequencing and copy number analysis of PITX2 and FOXC1 in 76 patients with syndromic or isolated ASD and related conditions. PITX2 mutations and deletions were found in 24 patients with dental and/or umbilical anomalies seen in all. Seven PITX2-mutant alleles were novel including c.708_730del, the most C-terminal mutation reported to date. A second case of deletion of the distant upstream but not coding region of PITX2 was identified, highlighting the importance of this recently discovered mechanism for ARS. FOXC1 deletions were observed in four cases, three of which demonstrated hearing and/or heart defects, including a patient with De Hauwere syndrome; no nucleotide mutations in FOXC1 were identified. Review of the literature identified several other patients with 6p25 deletions and features of De Hauwere syndrome. The 1.3-Mb deletion of 6p25 presented here defines the critical region for this phenotype and includes the FOXC1, FOXF2, and FOXQ1 genes. In summary, PITX2 or FOXC1 disruptions explained 63% of ARS and 6% of other ASD in our cohort; all affected patients demonstrated additional systemic defects with PITX2 mutations showing a strong association with dental and/or umbilical anomalies and FOXC1 with heart and hearing defects. FOXC1 deletion was also found to be associated with De Hauwere syndrome.
Journal Article