Evidence map›Paper›PMID 36401198›Full record

ArticleBMC neurology2022

Whole-genome analysis of monozygotic Brazilian twins discordant for type 1 narcolepsy: a case report.

João H C Campos, Ana C R Aguilar, Fernando Antoneli, Giselle Truzzi, Marcelo R S Briones, Renata C Ferreira, Fernando M S Coelho

Open access · goldAbstract readCase Reports
In one paragraph

Article in BMC neurology, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
0.4field-weighted citation impact, top 44% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed, 3 citations in OpenAlex.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors at 2 institutions in 2 countries.

João H C CamposCenter for Medical Bioinformatics, Escola Paulista de Medicina, UNIFESP, São Paulo, SP, Brazil.
Ana C R AguilarDepartment of Neurology and Neurosurgery, Escola Paulista de Medicina, UNIFESP, São Paulo, SP, Brazil.
Fernando AntoneliCenter for Medical Bioinformatics, Escola Paulista de Medicina, UNIFESP, São Paulo, SP, Brazil.
Giselle TruzziDepartment of Psychobiology, Escola Paulista de Medicina, UNIFESP, São Paulo, SP, Brazil.
Marcelo R S BrionesCenter for Medical Bioinformatics, Escola Paulista de Medicina, UNIFESP, São Paulo, SP, Brazil.
Renata C Ferreira *Department of Neurology and Neurosurgery, Escola Paulista de Medicina, UNIFESP, São Paulo, SP, Brazil. renata@epigene.com.br.ORCID http://orcid.org/0000-0003-1481-2926
Fernando M S Coelho *Department of Neurology and Neurosurgery, Escola Paulista de Medicina, UNIFESP, São Paulo, SP, Brazil.
Universidade Federal de São Paulo · BRMedigene (Germany) · DE

Funding

Conselho Nacional de Desenvolvimento Científico e Tecnológico 303912/2017-0Fundação de Amparo à Pesquisa do Estado de São Paulo 2020/08943-Fundação de Amparo à Pesquisa do Estado de São Paulo 2021/13111-1
6 · The paper itself

Abstract

backgroundNarcolepsy type 1 (NT1) is a rare and chronic neurological disease characterized by sudden sleep attacks, overwhelming daytime drowsiness, and cataplexy. When associated with a sudden loss of muscle tone (cataplexy) narcolepsy is classified as type 1, while the absence of cataplexy indicates type 2. Genetic, degenerative, and immunological hypotheses to explain the pathophysiology of NT1 are still a matter of debate. To contribute to the understanding of NT1 genetic basis, here we describe, for the first time, a whole genome analysis of a monozygotic twin pair discordant for NT1. CASE PRESENTATION: We present the case of a pair of 17-year-old male, monozygotic twins discordant for NT1. The affected twin had Epworth Sleepiness Scale (ESS) of 20 (can range from 0 to 24), cataplexy, hypnagogic hallucinations, polysomnography without abnormalities, multiple sleep latency tests (MSLT) positive for narcolepsy, a mean sleep latency of 3 min, sleep-onset REM periods SOREMPs of 5, presence of allele HLA-DQB1*06:02, and Hypocretin-1 level of zero pg/mL (normal values are > 200 pg/mL). The other twin had no narcolepsy symptoms (ESS of 4), normal polysomnography, MSLT without abnormalities, presence of allele HLA-DQB1*06:02, and Hypocretin-1 level of 396,74 pg/mL. To describe the genetic background for the NT1 discordant manifestations in this case, we present the whole-genome analysis of this monozygotic twin pair. The whole-genome comparison revealed that both twins have identical NT1 pathogenic mutations in known genes, such as HLA-DQB1*06:02:01, HLA-DRB1*11:01:02/*15:03:01. The affected twin has the expected clinical manifestation while the unaffected twin has an unexpected phenotype. The unaffected twin has significantly more frameshift mutations as compared to the affected twin (108 versus 75) and mutations that affect stop codons (61 versus 5 in stop gain, 26 versus 2 in start lost).

conclusionsThe differences observed in frameshift and stop codon mutations in the unaffected twin are consistent with loss-of-function effects and protective alleles, that are almost always associated with loss-of-function rare alleles. Also, overrepresentation analysis of genes containing variants with potential clinical relevance in the unaffected twin shows that most mutations are in genes related to immune regulation function, Golgi apparatus, MHC, and olfactory receptor. These observations support the hypothesis that NT1 has an immunological basis although protective mutations in non-HLA alleles might interfere with the expression of the NT1 phenotype and consequently, with the clinical manifestation of the disease.

Indexed as

CataplexyNarcolepsyBrazilHumansMaleOrexinsPolysomnographyOrexinsAutoimmune diseaseCase reportDiagnosticsDiscordant monozygotic twinsHLANarcolepsy type 1Whole-genome analysis

Identifiers

PMID36401198
PMCPMC9673436
OpenAlexW4309466691

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.