Kleine-Levin syndrome: an autoimmune hypothesis based on clinical and genetic analyses

BACKGROUND: Kleine-Levin syndrome (KLS) is a rare disorder of unknown etiology. Pathophysiologic hypotheses include a hypothalamic dysfunction and abnormalities in the central serotonin and dopamine metabolism. Several clinical symptoms also suggest an underlying autoimmune process. OBJECTIVE: To systematically investigate patients with KLS with reference to the available hypotheses. METHODS: The authors collected clinical, polysomnographic, CSF, CT, and MRI records and analyzed gene polymorphisms of HLA-DQB1, tryptophan hydroxylase (TpH), and catechol-O-methyltransferase (COMT) in 30 unrelated patients with KLS and their families. The genotype data were contrasted with data from a normal control population. RESULTS: Only human leukocyte antigen (HLA)-DQB1*0201 allele frequency was significantly increased in patients with KLS. Three patients with KLS but none of the control subjects were DQB1*0201 homozygous. Two affected subjects from the same family were DQB1*0201 homozygous. In 17 DQB1*0201 heterozygous parents, 11 (64.7%) had transmitted this allele, suggesting a preferential transmission. CONCLUSION: These findings, together with the young age at onset, the recurrence of symptoms, and the frequent infectious precipitating factors, suggest an autoimmune etiology for Kleine-Levin syndrome.     

Evidence for the genetic role of human leukocyte antigens in low frequency DRB1*1501 multiple sclerosis patients in Israel

A strong association exists between multiple sclerosis (MS) and the DRB1*1501 haplotype, in most populations. Linkage of Multiple Sclerosis (MS) with the MHC or HLA region on chromosome 6p21 has previously been observed in DRB1*1501 positive MS families. A group of 13 Israeli multiplex MS families with a very low frequency of DRB1*1501 haplotype were examined in this study. Association and a linkage test were performed in order to identify a non-DRB1*1501 effect of HLA on susceptibility for MS. MS multiplex families and healthy controls were molecularly typed for six highly polymorphic markers located within the MHC region: DRB1, DQA1 and DQB1, BAT-2, MIB and D6S248. Data analyses included: (a) an association study comparing the patient group with both healthy relative, and healthy control groups (b) a transmission test for linkage disequilibrium (TDT) of the MS-associated alleles in the multiplex families, and (c) multipoint non-parametric linkage (NPL) and parametric LOD score analyses using the GENEHUNTER program. The DRB1*1303 allele was significantly more frequent among the MS patients. There was a trend towards transmission disequilibrium of DRB1*1303, but was not statistically significant. Allele sharing and LOD score analyses revealed no evidence for linkage. The high frequency of DRB1*1303 observed in our family patients provides evidence to support the association with this allele that previously described in sporadic non-Ashkenazi MS patients. Thus, DRB1*1303 may serve as genetic risk factor for MS. Our study exemplifies the genetic heterogeneity in MS as there is a genetic effect of HLA on MS susceptibility in our low frequency DRB1*1501 patients.     

Neuromyelitis optica and multiple sclerosis in sisters

INTRODUCTION: The association of neuromyelitis optica (NMO) and multiple sclerosis (MS) has been reported, but details of the cases were not described. We report two Venezuelan Caucasian sisters with human leukocyte antigen (HLA) typing. RESULTS: Patient 1 fulfilled McDonald, et al. criteria with HLA A*24; B*07,*15; DRB1*01,*16 (DR2 positive). Patient 2 fulfilled the NMO revised criteria of Wingerchuck, et al. with HLA A*02,*24; B*07,*40; DRB1*04,*08, similar to Canadian aboriginal NMO cases and the Yukpa population from Venezuela. CONCLUSION: These cases confirmed the coexistence of NMO and MS in sisters, and further studies are needed to understand the genetic linkage between these diseases.     

Gene-environment interactions in multiple sclerosis: innate and adaptive immune responses to human endogenous retrovirus and herpesvirus antigens and the lectin complement activation pathway

Aspects of gene-environment interactions in multiple sclerosis (MS) were analysed in serum samples from 46 MS families (25 sporadic MS cases and 42 familial MS cases): antibodies to the MS-associated human endogenous retrovirus HERV-H, and levels of three components in the innate pathogen-associated molecular pattern recognition: mannan-binding lectin (MBL), and MASP-2 and MASP-3. For representative MS families, we also determined herpesvirus serology for HSV-1, VZV, and EBV; and tissue typed for HLA-B, and HLA DR and DQ. In MS, a significant correlation between elevated immune reactivity to HERV-H Env and disease activity was demonstrated, as were indications of a protective effect of high MBL and MASP-3 levels. The HLA alleles B*07, DRB*02, and DQB1*06 were commonly present together in the MS families, both in MS patients, and in unaffected family members. Our results support that HERV-H and the antiviral immune response may play a role in MS development, and also underline the tenuous nature of specific genetic contributions to this complex disease.     

A patient with both narcolepsy and multiple sclerosis in association with Pandemrix vaccination

Narcolepsy with cataplexy is caused by a selective loss of hypocretin-producing neurons, but symptomatic narcolepsy can also result from hypothalamic and brainstem lesions caused by multiple sclerosis (MS). We report a previously healthy man who developed clinical and laboratory verified narcolepsy without having any indication of hypothalamic lesions and MS after vaccination against the influenza H1N1 with Pandemrix. HLA typing showed both DRB1*15:01, associated with MS and DQB1*06:02, associated with narcolepsy. The genetic susceptibility in this patient makes it tempting to speculate upon an immune-mediated mechanism and a common etiology for both diseases in this patient.     

Familial multiple sclerosis: clinical, histocompatibility, and viral serological studies.

Evaluation of presumed "multiple sclerosis families" and comparison with recently reported families has led us to the following observations: (1) Seven of our original fourteen presumptive multiple sclerosis families had to be eliminated after personal clinical evaluation of family members failed to confirm the diagnosis in a second close relative. (2) No segregation of HLA type was noted between affected and unaffected individuals in our seven bona fide multiple sclerosis families, and no consistent segregation was noted in the twenty-eight families reported elsewhere. This supports other genetic evidence that there is not a single, major gene mapping in the HLA complex which predisposes to multiple sclerosis. (3) The DW2 antigen was increased in frequency among affected members of our families, and the A3 B7 haplotype was more frequent among affected members of other families reported. But unaffected members also tended to have an increased frequency of these same antigens. (4) No relationship was noted between HLA type and antimeasles antibody titer within our families.     

Autosomal dominant partial epilepsy with auditory features: description of a new family

PURPOSE: To report the clinical and genetic study of a new family with autosomal dominant partial epilepsy with auditory features (ADPEAF). METHODS: All the living affected members underwent a full clinical, neurophysiological, and magnetic resonance imaging (MRI) study. Genetic analysis was performed by typing their DNA with seven microsatellite markers previously found to cosegregate with ADPEAF on chromosome 10q24. RESULTS: The three living affected members had a childhood onset of rare and drug-responsive tonic-clonic seizures constantly preceded by a humming sensation. Routine and sleep electroencephalograms revealed rare and inconstant focal abnormalities over both temporal regions. MRI detected atrophy with increased T2 signal in the subcortical lateral portion of the right temporal lobe in one case. Analysis of 10q24 polymorphic alleles showed the same haplotype in all three affected members but different alleles in unaffected individuals. CONCLUSIONS: ADPEAF is a distinct condition with homogeneous clinical features. Genetic findings are consistent with linkage of ADPEAF to chromosome 10q24.     

Distribution of HLA-DQB1 alleles in patients with Kleine-Levin syndrome

Kleine-Levin syndrome (KLS) is a rare disorder characterized by recurrent episodes of hypersomnia, cognitive or behavior disturbances, compulsive eating behavior, and hypersexuality. The etiology of KLS remains unknown even though its clinical symptoms suggest an underlying autoimmune process. In this study, we analyzed the human leukocyte antigen (HLA) typing alleles in Taiwanese patients with KLS using the polymerase chain reaction sequence-specific priming technique. We report that an immunoresponsive HLA-DQB1, DQB110602, was detected in significant quantities in patients with KLS (three of 12, p = 0.046) and could elevate the risk of KLS (odds ratio, 1.143; 95% confidence interval, 0.0982–1.329). In conclusion, an identification of genomic susceptibility to KLS will be helpful in determining the immunospecific targeted therapies for patients with KLS.     

Novel mutation in the myelin protein zero gene in a family with intermediate hereditary motor and sensory neuropathy

OBJECTIVES: To determine the molecular basis for autosomal dominant intermediate hereditary motor and sensory neuropathy (HMSN) in a four generation family. The gene defects in families with intermediate HMSN are not known, but it has been suggested that most have X linked HMSN. METHODS: All participating family members were examined clinically. Genomic DNA was obtained from 10 affected and seven unaffected members. Linkage analysis for the known HMSN loci was first performed. Mutations in the peripheral myelin protein zero gene (PMP0) were sought in two affected members, using one unaffected member for comparison, by amplification of the six exons of the gene followed by single strand conformation polymorphism (SSCP) analysis, dideoxy fingerprinting (ddF), and sequencing. Subsequently, the mutation was screened for in all affected and unaffected members in the family using Alu I digestion and in 100 unrelated control subjects using "snap back" SSCP analysis. Sequencing of cDNA from a sural nerve biopsy from an affected member was also performed. RESULTS: The clinical phenotype was of variable severity, with motor nerve conduction velocities in the intermediate range. Linkage to PMP0 was demonstrated. Analysis of genomic DNA and cDNA for PMP0 identified a novel codon 35 GAC to TAC mutation. The mutation produces an inferred amino acid change of aspartate to tyrosine at codon six of the processed protein (Asp6Tyr) in the extracellular domain and was present in all affected family members but not in 100 unrelated controls. CONCLUSIONS: The present findings further extend the range of phenotypes associated with PMP0 mutations and indicate that families with "intermediate" HMSN need not necessarily be X-linked as previously suggested.     

A functional basis for the association of HLA class II genes adn susceptibility to multiple sclerosis: cellular immune responses to myelin basic protein in a multiplex family

This study has examined the cellular response to myelin basic protein (MBP) ina multiplex family with multiple sclerosis (MS). A total of 81 MBP-specific T cell liens (TCLs) were derived from three affected siblings and four healthy siblings. No difference was observed in estimated precursor frequenceis of MBP-specific TCLs or peptide specificity of TCLs when comparing affected and unaffected siblings. MPB-specific TCLs from affected siblings, however, were restricted to the DRw15/DQw6 allele more frequently than those from unaffected siblings (P < 0.02). These data suggest that restriction of autoantigen-specific T cells may be the functional basis for disease susceptibility related to HLA class II inheritance.     

HLA and major affective disorder

Fifteen unrelated multiplex families, each containing two or more offspring with a diagnosis of major affective disorder, were HLA typed to provide additional data bearing on the proposed linkage of affective disorder susceptibility genes with the major histocompatibility complex on chromosome 6. Altogether 19 parents, 38 affected children, and 13 unaffected children were typed. The distribution of shared HLA haplotypes among pairs of affected siblings, pairs of affected-unaffected siblings, and various diagnostic subsets of these families fails to lend any support for the HLA linkage hypothesis.     

Familial multiple sclerosis: volumetric assessment in clinically symptomatic and asymptomatic individuals.

A genetic basis for clustering of multiple sclerosis (MS) cases, based on studies of MS families, has been proposed for decades. Few reports provide detailed neurological as well as neuroradiological findings on these patients. We report total T2-weighted intracranial lesion volumes on members of three familial MS cohorts: a mother and father with conjugal MS with one affected son and a neurologically normal son and daughter, one pair of monozygotic twin sisters with MS, and a female sibling pair with MS. We hypothesized that asymptomatic siblings in a family with two affected parents and another affected child might demonstrate clinically silent T2-weighted lesions; and that monozygotic twins with MS are more likely to express similar T2-weighted lesion volumes than non-twin sibling pairs. We found clinically silent lesions in unaffected children of the symptomatic parent couple, with a significant difference in total T2 lesion volume between these unaffected siblings and their parents, as well as their affected brother. In our other sibling pairs, T2 lesion volumes were similar between the twins and significantly different in the non-twin pair, despite similar levels of clinical functioning as determined by EDSS scoring. These results suggest that foci of demyelination might be expected in clinically normal offspring of parents with MS, possibly reflecting a genetic predisposition to subsequent development of MS.     

Hodgkin's disease presenting in 1 of 4 siblings affected by hereditary spinocerebellar ataxia: clinical, immunological and genetic study

One of 4 siblings affected by hereditary spinocerebellar ataxia (HSCA) of Marie's type developed Hodgkin's disease (HD): the stage was IV B, the patient was submitted to conventional chemo- and radiotherapy and achieved complete remission. An accurate clinical, genetic and immunological study was carried out on all his family, including a complete HLA typing, a chromosome study, the immunophenotyping of peripheral blood mononuclear cells (PBMC), the PBMC response to polyclonal mitogens, to interleukin 2 (IL-2), to the association of PHA + IL-2 and the evaluation of the IL-2 receptor expression. No association was clearly demonstrable between an HLA haplotype and HSCA, while the patient with HSCA and HD was HLA-B18- and DQw3-positive (the last at homozygous level), two antigens known to be strongly associated with HD, mainly among the Sardinian ethnic group. The mode of inheritance of HD susceptibility is however completely different from that of Marie's HSCA. The chromosome study did not show any characteristic pattern of the karyotype, neither of the HSCA affected nor of the unaffected members. The immunological investigations did not elucidate any characteristic behavior of the family members, apart from the typical findings of HD seen on patients with HSCA and HD. Our study could not demonstrate any genetic and/or immunologic common background shared by the two diseases, HSCA and HD. Their coexistence in our patient, although the statistic probability is very low, seems to be a fortuitous coincidence more than the result of a common genetic and pathogenetic mechanism.     

Abnormal phonologic processing in familial lateral temporal lobe epilepsy due to a new LGI1 mutation

PURPOSE: Autosomal dominant lateral temporal lobe epilepsy (ADLTLE) is a rare familial epilepsy with onset in adolescence or early adulthood, associated with mutations of LGI1 in most families. We describe the clinical, neuropsychological, and molecular genetic study of a new ADLTLE Italian family. METHODS: A four-generation family from Sardinia was studied. Clinical, neuropsychological, and genetic analysis were performed in eight living affected family members. RESULTS: Nine family members had seizures over four generations; four of them had auditory auras and aphasia followed by secondarily generalized tonic-clonic seizures (SGTCs). One individual in addition had visual symptoms, and one family member had only vertigo followed by SGTCs. The side of seizure onset could not be determined in these five patients with focal seizures. The proband had febrile and afebrile tonic-clonic seizures. Two family members had only febrile seizures. Inheritance was autosomal dominant with 59% penetrance. Genetic molecular analysis showed a new LGI1 missense mutation causing a Leu154Pro substitution in six affected and one unaffected individuals. Dichotic listening performance was abnormal in four affected individuals compared with controls. Fluency and lexical abilities also were pathological in three patients. These findings showed that in patients, the left temporal lobe was less specialized in the auditory processing function than in controls. CONCLUSIONS: In this ADLTLE family, both seizure semiology and neuropsychological findings point to a lateral temporal lobe dysfunction. The newly identified LGI1 mutation might underlie both the seizure disorder and the neuropsychological deficits.     

Sardinian multiple sclerosis is associated with HLA-DR4: a serologic and molecular analysis

HLA haplotypes in 45 unrelated Sardinian multiple sclerosis patients and in six multiplex families were defined, using both serologic and restriction fragment length polymorphism (RFLP) analysis. In unrelated MS patients, we found an association with HLA-DR4 (p less than 0.01, relative risk = 2.5) and DQw3 (p less than 0.04, relative risk = 2.2). Using a beta-DR cDNA probe, we observed no variation of the DR4 RFLP profile in sporadic or related MS patients compared with DR4-specific pattern in controls. Using a beta-DQ cDNA probe, we identified two DQw3 patterns (DQw3.1 and DQw3.2) with similar frequency in patients and in controls. No specific RFLPs were observed in association with different disease courses. The frequency of haplotype sharing in affected members of multiplex families was not different from that expected by chance. This study shows that Sardinian MS patients carry predominantly the HLA-DR4 allele, in contrast to the DR2 prevalence reported in Caucasian populations. The lack of association with HLA haplotypes in affected members of multiplex families may indicate that genetic factors outside the HLA system play a substantial role in families with MS.     

Clinical demographics of multiplex families with multiple sclerosis

The demographic and clinical characteristics of 89 multiplex families whose affected members meet proposed diagnostic criteria for multiple sclerosis (MS) genetic research are described and compared with 425 sporadic cases of MS and other published collections of MS multiplex families. The proportion of affected multiplex family members who experienced gradual progression of disability from onset (primary progressive MS) is lower than reported by other investigators. Different phenotypes of MS may reflect genetic heterogeneity that may partially explain inconsistencies in the results of genetic linkage studies. Clinical details of affected multiplex family members must be described so that comparisons of genetic results across studies can be properly interpreted.     

A MYH3 mutation identified for the first time in a Chinese family with Sheldon-Hall syndrome (DA2B)

Sheldon-Hall syndrome is the most common type of distal arthrogryposis syndromes, also known as distal arthrogryposis 2B (DA2B). Sheldon-Hall syndrome is caused by mutations in the TPM2, TNNI2, TNNT3 or MYH3 gene and characterized by ulnar deviation, camptodactyly, overlapping fingers and scoliosis from birth. We investigated a Chinese family with multiple members who clinically presented with distal arthrogryposis of the hands. In total, 261 subjects including one proband and ten family members from the non-consanguineous Chinese family and 250 healthy volunteers were included and had their genomic DNA extracted. A novel missense mutation in exon 13 of the MYH3 gene, c.1160A > G (p.Tyr387Cys), was identified in the proband and his father through whole-exome sequencing. The proband and six affected family members were confirmed to carry this mutation by Sanger sequencing, although the mutation was not detected in the four unaffected individuals or 250 volunteers. This is the first report of a novel MYH3 mutation being identified as the cause of DA2B in a Chinese family. Our findings confirm that MYH3 gene mutations can be a pathogenic cause of DA2B in Asian patients. This study increases the mutational spectrum in MYH3 and aids genetic counseling and prenatal diagnosis.     

A Family with Hereditary Spastic Paraparesis and Epilepsy

Summary: Purpose: We describe a family with hereditary spastic paraparesis (HSP) in which 4 of 6 affected members also have epilepsy.
Methods: All family members were examined by 2 neurologists. Four affected and 3 unaffected family members had EEG recordings. Four affected members were investigated for other causes of spastic paraparesis and epilepsy.
Results: Epileptic symptoms varied among family members: 1 had complex partial seizures, another had focal myoclonic epilepsy, and 2 had simple partial seizures secondarily generalized. All 4 had clinical or EEG evidence to support a focal origin for the epilepsy, and 2 had photoparoxysal responses on EEG. Symptoms were more severe and occurred earlier in the younger generation, suggesting genetic anticipation in this family. The onset of epilepsy developed simultaneously with, or ≤18 years before, onset of gait disturbance. Three unaffected family members had normal EEGs.
Conclusions: The association of HSP and epilepsy should no longer be assumed to be fortuitous.     

Childhood onset in familial prion disease with a novel mutation in the PRNP gene

BACKGROUND: Up to 15% of cases of prion diseases are due to the autosomal dominant inheritance of coding PRNP mutations. OBJECTIVE: To describe the unique clinical and genetic findings in a family of East Indian origin with autosomal dominant inheritance of a novel PRNP mutation. DESIGN: Detailed neurological examination and sequencing analysis of the MAPT and PRNP genes. SETTING: Toronto Western Hospital, Toronto, Ontario. PATIENTS: Five available members of a family of East Indian origin with a rapidly progressive neurodegenerative disorder characterized by dementia, motor decline, and ataxia. RESULTS: We identified a novel Pro105Thr mutation in the PRNP gene in all of the 3 clinically affected family members but not in their unaffected relatives or normal controls. Although 5 of 6 affected family members had a relatively homogeneous phenotype and age at onset (range, 33-41 years), 1 of the 6 patients developed the disease at age 13 years. CONCLUSIONS: A novel mutation in the PRNP gene was identified in all of the available, clinically affected members of this family with a rapidly progressive neurodegenerative disease. To our knowledge, the propositus represents the youngest individual with inherited prion disease described to date.     

HLA study of 21 families with two or more members affected by febrile convulsions

21 Italian families with at least two members who had had febrile convulsions (FC) were HLA-typed for class I antigens. A total of 49 subjects and 43 close relatives (parents or sibs) were examined. No single antigen or haplotype was statistically more frequent among pooled FC subjects. The study, however, is not conclusive regarding a relationship between FC and HLA region because of the possible genetic heterogeneity of proneness to FC. In a significant proportion of cases two FC affected sibs had unaffected parents: besides the models of inheritance so far proposed for this pathology, the involvement of two complementary dominant factors was also considered. The report includes uncommon cases: a family where one FC affected parent transmitted the same HLA haplotype to all three affected sibs; two more families, with both parents and progeny affected by FC. The HLA typing of all members of these unusual families, although not furnishing relevant information at present, may be of value to other investigators.

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Sommario è stata effettuata la tipizzazione del sistema HLA, antigeni della classe 1, in 21 famiglie in cui almeno 2 membri avevano manifestato convulsioni febbrili (CF). Sono stati esaminati un totale di 49 soggetti e 43 consanguinei di I⁰ grado (genitori o fratelli). Non sono risultati statisticamente più frequenti, nell’insieme dei soggetti affetti da CF, nè un singolo antigene nè un aplotipo. La ricerca comunque non consente di trarre ipotesi conclusive circa il rapporto tra CF e regione HLA, a causa della possibile eterogeneità genetica della suscettibilità alle CF stesse. In una proporzione di casi significativa due fratelli con CF avevano genitori sani: è stata presa in considerazione, oltre i modelli di trasmissione ereditaria finora proposti per questa affezione, anche la possibile implicazione di due fattori complementari dominanti. Tra i casi studiati alcuni appaiono non comuni: per esempio una famiglia dove un genitore con CF aveva trasmesso lo stesso aplotipo HLA ai 3 figli affetti e, ancora, 2 famiglie con entrambi i genitori e i figli affetti da CF. La tipizzazione HLA di tutti i membri di queste famiglie atipiche, anche se non dà informazioni di rilievo nell’attualità, può essere utile per altri ricercatori.