OBJECTIVE: To test the hypothesis that monogenic neuropathies such as Charcot-Marie-Tooth disease (CMT) contribute to frequent but often unexplained neuropathies in the elderly, we performed genetic analysis of 230 patients with unexplained axonal neuropathies and disease onset ≥35 years. METHODS: We recruited patients, collected clinical data, and conducted whole-exome sequencing (WES; n = 126) and MME single-gene sequencing (n = 104). We further queried WES repositories for MME variants and measured blood levels of the MME-encoded protein neprilysin. RESULTS: In the WES cohort, the overall detection rate for assumed disease-causing variants in genes for CMT or other conditions associated with neuropathies was 18.3% (familial cases 26.4%, apparently sporadic cases 12.3%). MME was most frequently involved and accounted for 34.8% of genetically solved cases. The relevance of MME for late-onset neuropathies was further supported by detection of a comparable proportion of cases in an independent patient sample, preponderance of MME variants among patients compared to population frequencies, retrieval of additional late-onset neuropathy patients with MME variants from WES repositories, and low neprilysin levels in patients' blood samples. Transmission of MME variants was often consistent with an incompletely penetrant autosomal-dominant trait and less frequently with autosomal-recessive inheritance. CONCLUSIONS: A detectable fraction of unexplained late-onset axonal neuropathies is genetically determined, by variants in either CMT genes or genes involved in other conditions that affect the peripheral nerves and can mimic a CMT phenotype. MME variants can act as completely penetrant recessive alleles but also confer dominantly inherited susceptibility to axonal neuropathies in an aging population.

• MeSH
• Charcotova-Marieova-Toothova nemoc krev   genetika   MeSH
• genetická predispozice k nemoci genetika   MeSH
• hereditární motorické a senzitivní neuropatie krev   genetika   MeSH
• lidé středního věku MeSH
• lidé MeSH
• neprilysin krev   genetika   MeSH
• sekvenování exomu MeSH
• senioři MeSH
• stárnutí * krev   MeSH
• věk při počátku nemoci MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• neprilysin MeSH

Malformations of cortical development (MCD) comprise a broad spectrum of developmental brain abnormalities. Patients presenting with MCDs often suffer from drug-resistant focal epilepsy, and some become candidates for epilepsy surgery. Their likelihood of achieving freedom from seizures, however, remains uncertain, and depends in a major part on the underlying pathology. Tissue samples obtained in epilepsy surgery form the basis of definite histopathological diagnosis; however, new molecular genetic methods have not yet been implemented in diagnostic processes for MCD cases. Furthermore, it has not been completely understood how the underlying pathology affects patients' outcomes after epilepsy surgery. We performed a systematic literature review of studies describing both histopathological and molecular genetic findings in MCD, along with studies on epilepsy surgery outcomes. We aimed to correlate the genetic causes with the underlying morphological abnormalities in focal cortical malformations and to stress the importance of the underlying biology for patient management and counseling. From the summarized findings of multiple authors, it is obvious that MCD may have a diverse genetic background despite a similar or even identical histopathological picture. Even though most of their molecular genetic findings converge on various levels of the PI3K/AKT/mTOR pathway, the exact mechanisms underlying MCD formation have not yet been completely described or indeed how this pathway generates a diverse range of histological abnormalities. Based on our findings, we therefore propose that all patients diagnosed and operated for drug-resistant epilepsy should have an integrated molecular and pathological diagnosis similar to the current practice in brain tumor diagnostic processes that might lead to more accurate diagnosis and effective stratification of patients undergoing epilepsy surgery.

• Klíčová slova
• mTOR, epilepsy surgery, malformations of cortical development, neuropathology, somatic variant,
• MeSH
• epilepsie genetika   patologie   MeSH
• fosfatidylinositol-3-kinasy MeSH
• genetické asociační studie MeSH
• lidé MeSH
• malformace mozkové kůry genetika   patologie   MeSH
• mozek abnormality   patologie   MeSH
• mozková kůra patologie   MeSH
• nemoci mozku patologie   MeSH
• refrakterní epilepsie genetika   patologie   MeSH
• signální transdukce MeSH
• TOR serin-threoninkinasy MeSH
• záchvaty patologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• systematický přehled MeSH
• Názvy látek
• TOR serin-threoninkinasy MeSH

Hereditary motor and sensory neuropathy-type Lom (HMSNL), also known as CMT4D, a demyelinating neuropathy with late-onset deafness is an autosomal recessive disorder threatening Roma population worldwide. The clinical phenotype was reported in several case reports before the gene discovery. HMSNL is caused by a homozygous founder mutation p.Arg148* in the N-Myc downstream-regulated gene 1. Here, we report findings from the Czech Republic, where HMSNL was found in 12 Czech patients from eight families. In these 12 patients, 11 of the causes were due to p.Arg148* mutation inherited from both parents by the autosomal recessive mechanism. But in one case, the recessive mutation was inherited only from one parent (father) and unmasked owing to an uniparental isodisomy of the entire chromosome eight. The inherited peripheral neuropathy owing to an isodisomy of the whole chromosome pointed to an interesting, less frequent possibility of recessive disease and complications with genetic counseling.

• MeSH
• Charcotova-Marieova-Toothova nemoc diagnóza   etnologie   genetika   patofyziologie   MeSH
• dítě MeSH
• dospělí MeSH
• efekt zakladatele MeSH
• exprese genu MeSH
• fenotyp MeSH
• genetické poradenství MeSH
• genotyp MeSH
• geny recesivní MeSH
• hluchota patofyziologie   MeSH
• intracelulární signální peptidy a proteiny genetika   MeSH
• lidé MeSH
• lidské chromozomy, pár 8 chemie   MeSH
• mutace * MeSH
• předškolní dítě MeSH
• proteiny buněčného cyklu genetika   MeSH
• Refsumova nemoc diagnóza   etnologie   genetika   patofyziologie   MeSH
• Romové * MeSH
• uniparentální disomie * MeSH
• věk při počátku nemoci MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• intracelulární signální peptidy a proteiny MeSH
• N-myc downstream-regulated gene 1 protein MeSH Prohlížeč
• proteiny buněčného cyklu MeSH