Este documento presenta información sobre la enfermedad de Huntington y fenocopias de Huntington. Describe la enfermedad de Huntington como una poliglutaminopatía causada por una expansión del triplete CAG en el gen HTT. Explica los criterios diagnósticos, la evolución clínica y las características epidemiológicas. También discute las fenocopias de Huntington, definidas como un cuadro clínico similar a la enfermedad de Huntington pero con un resultado genético negativo, siendo las expansiones C9orf72 una de las causas
11. LABORATORIO
EXAMEN POSIBLE DIAGNÓSTICO
Ceruloplasmina, Cupremia,
Cupruria
Enfermedad de Wilson
Ferritina Neuroferritinopatía
Ac. Antigliadina Enfermedad celiaca
N. Plomo sérico Intoxicación por plomo
Ac. Antineuronales (CRMP5/CV2,
Anti-hu, Yo, NMDA)
Sd. Paraneoplásicos
Lactato/Piruvato Tr. Mitocondriales – Metabólicos
Alfa fetoproteína Ataxia Telangiectasia, AOA 1 y 2
Ag Kell y Kx Eritrocitario Mc Leod
EEG Creutzfeldt Jackob, Sd. Asociados a epilepsias
Punción Lumbar Paraneoplásico- Inflamatorio
Biopsia Muscular Mitocondriopatías
Ruth H. Walker. Differential Diagnosis of Chorea. Curr Neurol Neurosci Rep (2011) 11:385–395
12. ESTUDIO SEGÚN PERFIL DE INSTALACIÓN
Wild, EJ; Tabrizi, SJ. The differential diagnosis of chorea. Practical Neurology 2007, 7 (6) 360-373
ENFERMEDAD
DE
HUNTINGTON
23. DIAGNÓSTICO ENFERMEDAD DE
HUNTINGTON
Portador una mutación por expansión CAG en el gen de EH ó
Historia Familiar de EH
+
Desarrollo de síntomas motores “inequívocos” de EH,
definidos por “nivel de certeza diagnóstica” en la escala UHDRS:
1. = Normal (sin alteración motora)
2. = Alteraciones motoras inespecíficas
3. = Alteraciones motoras que pueden ser signos de EH (50-89%
confianza)
4. = Alteraciones motoras que probablemente son signos de EH
(90-98% Confianza)
5. = Alteraciones motoras que son signos inequívocos de EH
(>99%)
Reilmann et al. Diagnostic Criteria for Huntington’s Disease Based on Natural History. Movement Disorders, Vol. 29, No. 11, 2014
25. CRITERIOS DIAGNÓSTICOS
Reilmann et al. Diagnostic Criteria for Huntington’s Disease Based on Natural History. Movement Disorders, Vol. 29, No. 11, 2014
27. INCIDENCIA
ENFERMEDAD DE HUNTINGTON
Pringsheim T, Wiltshire K, Day L, et al. The incidence and prevalence of huntington´s disease: a systematic review and meta analysis. Mov Disord
2012;27(9):1083-1091
28. PREVALENCIA
ENFERMEDAD DE HUNTINGTON
Pringsheim T, Wiltshire K, Day L, et al. The incidence and prevalence of huntington´s disease: a systematic review and meta analysis. Mov Disord
2012;27(9):1083-1091
Asia
Europa
Norte América
31. PREVALENCIA EN CHILE
Ricardo Cruz-Coke, Rodrigo S Moreno.
Genetic epidemiology of single gene defects in Chile.
J Med Genet 1994;31:702-706
Enfermedad de Huntington
CHILE
1/25.000
(0,25/100.000)
Chile 2013: 17.62 millones
EH ~ 705
¿Menor que Asia?
32. PREVALENCIA EN CHILE
Ricardo Cruz-Coke, Rodrigo S Moreno.
Genetic epidemiology of single gene defects in Chile.
J Med Genet 1994;31:702-706
34. ESTUDIO SEGÚN PERFIL DE INSTALACIÓN
Wild, EJ; Tabrizi, SJ. The differential diagnosis of chorea. Practical Neurology 2007, 7 (6) 360-373
ENFERMEDAD
DE
HUNTINGTON
35. Fenocopias de enfermedad de Huntington
Clínica Símil a Enfermedad de Huntington
& Test Genético Negativo Para EH
36. Síndrome Fenocopia
Enfermedad de Huntington
Presentación clínica consistente con enfermedad de
Huntington (evaluado por un neurólogo experto o
neuro-genetista), con un test genético negativo para
expansión de repeticiones CAG en el gen HTT
C9orF72 expansions are the most common genetic cause of Huntington disease phenocopies. Neurology 2014; 82:292-
299
43. ATAXIA
SCA-17 (HDL-4):
Ataxia/ Corea, Distonía, Parkinsonismo
SCA1 y SCA2:
Corea menos frecuente y más lento
SCA7:
Corea distal u orofacial leve
SCA 14:
Corea de las manos
ADRPL:
Corea, Mioclonías, Ataxia
Sd. Neuroacantocitosis:
Mioclonias (<20 años)
Ataxia (>40 años)
J Neurol Neurosurg Psychiatry 2013;84:650-656 doi:10.1136/jnnp-2012-302532
44. ATAXIA
Ataxia de Friedreich:
Corea es una manifestación rara, involucra la lengua,
marcha y extremidades
(segunda década).
Escoliosis marcada
Cardiomiopatía
Ataxia Telangiectasia:
Corea
Distonía
Hipomimia (90%)
Inicio 1° década
J Neurol Neurosurg Psychiatry 2013;84:650-656 doi:10.1136/jnnp-2012-302532
45. Trastorno de la Marcha
Corea + Distonía + Neuropatía Periférica:
Coreoacantocitosis y Mc Leod
Distonía + Rigidez + Bradicinesia + Espasticidad:
PKAN, EW, Formas parkinsonianas de HDL-2
Corea+ Marcha Atáxica:
SCAs, ADRPL
AF, AT, AOA
J Neurol Neurosurg Psychiatry 2013;84:650-656 doi:10.1136/jnnp-2012-302532
46. OCULOMOTILIDAD
Enf. Huntington Wilson, Coreo-acantocitosis y PKAN
lentitud en inicio de sacadas
Sacadas lentas e hipométricas
Alteración en la fijación visual
Sd. Kufor-Rakeb:
PSM (sacadas verticales ascendentes) y parkinsonismo respondedor a L-Dopa
Corea Acantocitosis:
Fraccionamiento de sacadas
Square-wave jerks
AOA tipo 1 y 2, AT, EH
Apraxia Oculomotora
SCAs
Movimientos oculares cerebelosos:
Dismetria de sacadas, square wave jerks, flutter ocular, nistagmo
J Neurol Neurosurg Psychiatry 2013;84:650-656 doi:10.1136/jnnp-2012-302532
47. Crisis Epilépticas
EH sólo en variante juvenil (30-50% c/inicio<10
años)
SCA-17 22%
Coreo acantocitosis 66% (50% 1°
manifestación)
Mc Leod 40%
HDL1 en su mayoríaJ Neurol Neurosurg Psychiatry 2013;84:650-656 doi:10.1136/jnnp-2012-302532
48. COGNITIVO-CONDUCTUAL
SCA-17 75-90% Demencia fronto-subcortical y
síntomas psiquiátricos similares a EH en el 25-30%
HDL2 Sd. Cognitivo-conductual más leve y de
progresión más lenta que EH
HDL1 Puede tener un perfil similar a EH
ADRPL 90% Demencia fronto-subcortical y 80%
alt. conductuales
Coreoacantocitosis similar a EH, + conductas
compulsivas como automutilación o
tricotilomanía
PKAN indistinguible de EH juvenil
J Neurol Neurosurg Psychiatry 2013;84:650-656 doi:10.1136/jnnp-2012-302532
49. Inicio Adulto:
Ancestro SudAfrica: HDL2
Origen Japones: DRPLA
Frances o Inglés: Neuorferritinopatía
Finlandez: SCA8
Juvenil:
Franco-Canadiense: AOA Tipo 2
Inicio Adulto:
Facio-Buco-Lingual: Coreoacantocitosis, McLeod (Hombres) o
Neuroferritinopatía
Head Drop o Banging; Coreo-Acantocitosis
Adulto:
SCA17, DRPLA, SCA1, SCA2, SCA7, SCA 14, SCA8
Juvenil:
Friedreich, Ataxia Telangiectasia, AOA Tipo 1 y 2
Adulto
SCA17, DRPLA, SCA1, SCA2, SCA 7, SCA14, SCA8
Apariencia de “Hombre de Goma”: Coreoacantocitosis o McLeod
Juvenil
Friedreich, Ataxia Telangiectasia, AOA Tipo 1 y 2
Adulto:
Sacadas Dismétricas, square-wave jerks, seguimiento sacádico,
Nistagmo: SCAs, DRPLA, Coreo-Acantocitosis
Juvenil:
Friedreich
Apraxia Oculomotora: Ataxia Telangiectasia. AOA tipo 1 y 2
Adultos: HDL-1, Coreo-Acantocitosis, DRPLA. SCA17
ALTERACIONES CONDUCTUALES
Adultos: Automutilación: Coreo-Acantocitosis, Lesch-Nyhan
Inicio Adulto:
Ancestro SudAfrica: HDL2
Frances o Inglés: Neuorferritinopatía
Inicio Adulto:
Facio-Buco-Lingual: PKAN, Enf. Wilson, Lesch Nyhan, Sd Kufor Rakeb,
Aceruloplasminemia
Adulto:
SCA17, SCA 2
Adulto
HDL-2
Juvenil
PKAN, Enf. Wilson, PLAN, Sd. Kufor Rakeb
ETNIA
REGIÓN
CORPORAL
ATAXIA
CEREBELOSA
COMPROMISO DE
LA MARCHA
Juvenil:
Paralisis supranuclear de la mirada Precoz: Sd. Kufor Rakeb
ALTERACIONES DEL HABLA:
Inicio Juvenil Palilalia, Taquilalia, Disartria: PKAN
ALTERACIÓN DE
MOTILIDAD
OCULAR
CRISIS
EPILÉPTICAS
ALTERACION
CONDUCTUAL
Síntomas tipo EHPREDOMINIO COREA
PREDOMINIO
DISTONÍA/PARKINSONISMO
J Neurol Neurosurg Psychiatry 2013;84:650-656 doi:10.1136/jnnp-2012-302532
52. Schneider SA et al. (2007) The Huntington's disease-like syndromes: what to consider in patients with a negative Huntington's disease
gene test Nat Clin Pract Neurol 3: 517–525 10.1038/ncpneuro0606
COREA HEREDODEGENERATIVO
AD AR/Ligado al X
54. HETEROGENEIDAD CLINICA Y GENÉTICA
Wild, EJ; Mudanohwo, EE; Sweeney, MG; Schneider, SA; Beck,
J; Bhatia, KP; Rossor, MN; Davis, MB; Tabrizi, SJ; (2008)
Huntington's disease phenocopies are clinically and genetically
heterogeneous. Movement Disorders , 23 (5) 716 - 720
285 patients with syndromes
consistent with HD, who were HD
expansion-negative, were screened
for mutations in PRNP, JPH3, TBP,
DRPLA, SCA1, SCA2, SCA3, FTL
and FRDA.
55. CONCLUSIÓN
El enfrentamiento diagnóstico de Corea depende del
perfil de instalación y fenomenología asociada
Entre los cuadros Heredodegenerativos EH debe ser
nuestra primera sospecha diagnóstica
Posiblemente en Chile exista un subdiagnóstico de
la EH
Las Fenocopias de EH son en general
enfermedades raras y de difícil diagnóstico
En Chile el dificil acceso a el estudio genético
dificulta el diagnóstico en Corea
Heredodegenerativo
Notas del editor
MECANISMO PATOGÉNICO
(1) HTT es transladado para producir proteina Huntingtina de longitud completa asi como un fragmento Exon 1 Amino-Terminal HTT (por splicing aberrante). La longitud de la poliglutamina (PolyQ) en estas proteinas depende de la extensión de la inestabilidad somática. (2) La Huntingtina de longitud completa es clivada por proteolisis para generar fragmentos. (3) Fragmentos entran en el nucleo (4) Son retenidos en el nucleo por auto-asociación, oligomerización y agregación- Llevando a la formación de inclusiones, un proceso que causa disregulaicón transcripcional por secuestro de otras proteinas y otros mecanismos no bien definidos. (5) Los fragmentos oligomerizados de huntingtina se agregan en el citoplasma (6) la agregacion de huntingtina se exacerba a traves de la alteración de redes de proteostasis, que tambien generan alteraciones globales (7) Las formas aberrantes generan mayor alteración celular, disfucnión sinaptica, toxicidad mitocondrial y disminución en la tasa de transporte axinal.
Figure 1 | Natural history of clinical Huntington disease. The normalized CAG age product (CAP) score enables progression of many individuals with different CAG expansion lengths to be plotted on the same graph. Mean disease onset is at CAP score ~100 (typically ~45 years of age), but there is substantial interindividual variability. Without normalization, the CAP score at onset exceeds 400. The period before diagnosable signs and symptoms of Huntington disease occur is termed ‘premanifest’. During the ‘presymptomatic’ period, no signs or symptoms are present. In ‘prodromal’ Huntington disease, subtle signs and symptoms are present. Manifest Huntington disease is characterized by slow progression of motor and cognitive difficulties, and chorea is often prominent early but plateaus or even decreases later. Fine motor impairments (incoordination, bradykinesia and rigidity) progress more steadily. Figure adapted from REF. 6, Nature Publishing Group.
Para propósitos de investigación una vez que aparecen síntomas de puntaje =4 esta es la confirmación formal del inicio de síntomas motores
Motor Diagnosis: The Huntington Disease Rating Scale (UHDRS) diagnostic confidence level (DCL) is the standard measure used for clinical diagnosis in at-risk individuals and is based solely on the motor evaluation. It is a categorical scale (Table 1A) with a range from 0 (normal) to 4 (unequivocal signs of HD, ≥99% confidence ≥ on the part of the examiner). The DCL has previously shown fair inter-rater reliability (weighted kappa = 0.67, SE = 0.09) (Hogarth et al., 2005). Participants had a clinical diagnosis of HD at the time of the first rating of a DCL = 4. Multidimensional Diagnosis: Question 80 (Q80) of the UHDRS asks raters to take into account all aspects of the UHDRS (motor, cognitive, behavioral, and functional) and to make a decision (yes or no) whether a subject has a diagnosis of HD with a confidence level 99% (Table 1B). The first occurrence of Q80 = yes was the multidimensional diagnostic criteria used for the current analyses.
In participants with prodromal HD enrolled in the PREDICT-HD study, a multidimensional diagnosis occurs earlier and with less motor and cognitive impairment than a diagnosis based on the motor examination. Given the results of our analysis, a diagnosis that considers cognitive and behavioral features in addition to motor features has face validity. Therefore, compared to the traditional motor diagnosis, a multidimensional diagnosis may be a preferable outcome for use in future trials aimed at delaying the manifestation of HD.
A multidimensional diagnosis occurs earlier and with less motor and cognitive impairment than the traditional motor diagnosis and identifies clinical phenotypes that may have predominant non-motor features. A staging system in prodromal HD, similar to that proposed in AD, may be of value. A better understanding of diagnostic decision making may allow for better standardization of diagnosis, and the development of clear criteria for research and clinical diagnoses that may be utilized as an outcome measure in future trials aimed at delaying diagnosis in prodromal HD.
Corea, distonia o diskinesias de la region buco-linguo-masticatoria, son precipitados típicamente por el comer, con protrusión de la lengua y automutilación de la lengua y mordedura de labios. Estos pacientes se pueden presentar también con espasmos del cuello violentos, con subita flexoextensión que puede llevar a “head drop” y “head banging”. Las vocalizaciones y disartria estan presentes pero el parkinsonismo es raro. La co-ocurrencia de arreflexia, debilidad y atrofia muscular, sugerente de Neuropatia periférica y/o miopatía concomitante, pueden ayudar en el diagnóstico.
Mc Leod afecta gb, musculos, snp y miocardio. Se presenta con corea que puede involucrar la region facio bucal y vocalizaciones pero casi nunca con mordedura de lengua o labios, disfagia o parkinsonismo. 60% Desarrollan cardiomiopatía con FA
PKAN (NBIA1) es AR 1-3 por millon causado por mutacion PANK2 que codifica para pantotenato kinasa, una enzima relevante en la síntesis de Coenzima A desde Vitamina B5 y asociada con el metabolismo lipidico. 90 % inicia antes de los 6 años, se presenta con distonía generalizada con compromiso facio-bucolingual, habitualmente como DISTONIA DE BOCA ABIERTA. El parkinsonismo puede ser un síntoma de presentación, y tambien puede ocurrir coreoatetosis, tics y piramidalismo. 1/3 desarrollan retinitis pigmentosa
Atrofia cerebelosa marcada solo ha sido reportada infrecuentemente en EH juvenil
Cuando la EH presenta síntomas cerebelosos, estos son muy leves
SCA-17_ 0.5-1.8% HD-Like: Edad de inicio entre 19 y 48 años, rara vez inicia en la infancia- AD por mutacion del gen TBP que codifica para TATA-box binding protein
Inestabilidad intergeneracional especialmente por transmisión paterna.
Ataxia cerebelosa es el síntoma más frecuente pero puede ser muy heterogeneo. Distonia y corea son los 2 más frecuentes trastornos del movimiento. Cuando se agrega parkinsonismo SCA-17 Puede imitar AMS, aunque sin clara disfunción Autonómica, y DAT- SCAN puede ser anormal
ADRPL: Mutación por expansión CAG en el gen ATN1 que codifica para Atrofina-1, presenta anticipación, Inicio en la tercera década
AF generalmente inicia en las primeras 2 decadas, ataxia AR más comun 1/50000, caracterizada por ataxia de tronco y extremidades progresivo, arreflexia EEII, Babinski, Disatria, Hipopalestesia y alt propiocepcion, problemas visuales, escoliosis, pie cavo, cardiomiopatia. Corea Generalizado involucra la lengua y afecta la marcha y destreza manual es una manifestación rara con inicio en la segunda década. En estos casos la ataxia se inició tardiamente. Escoliosis marcada y cardiomiopatía era un elemento atipico para EH
Fig. 1 a The initial approach to the patient with chorea. b A diagnostic approach to children/infants with chorea after negative testing for Sydenham’s chorea. c A diagnostic approach to adults with chorea after negative testing for Huntington’s disease
Huntington’s disease (HD) is a fatal neurodegenerative disorder with autosomal dominant inheritance that typically presents with a triad of movement disorder, cognitive dysfunction and behavioural problems, but the disease can arise in the absence of a family history and its clinical presentation and course are highly variable.1 HD is caused by a CAG triplet expansion in the IT-15 gene encoding huntingtin.2 Approximately 1% of subjects with symptoms and signs suggestive of HD do not have the HD expansion. 3, 4 Such patients, referred to as HD phenocopies, present a diagnostic challenge. HD phenocopies are known to be produced by several neurogenetic syndromes5 . These include the HD-like syndromes HDL1 (caused by an octapeptide repeat insertion in PRNP) 6 and HDL2 (caused by mutations in JPH3). 7 There is also clinical overlap between HD and dentatorubral-pallidoluysian atrophy (DRPLA)8 and the autosomal dominant spinocerebellar ataxias including SCA1, SCA2, SCA3, SCA12 and SCA17 (HDL4). 9 Friedreich’s ataxia has not previously been described as an HD phenocopy but is known to cause chorea.10 Neuroferritinopathy, caused by mutations in the ferritin light chain gene (FTL), is an autosomal dominant basal ganglia disease with features similar to those of HD.11 Identifying the genetic basis of HD phenocopies is clinically important in the differential diagnosis of such patients, and has the potential to inform the search for genetic modifiers and intervention strategies for HD. From samples referred for HD genetic testing, we identified 285 patients with syndromes consistent with a diagnosis of HD, in whom the HD expansion was not detected. DNA samples were tested for the mutations causing HDL1, HDL2, DRPLA, SCA1, SCA2, SCA3, SCA17, neuroferritinopathy and FA. We present the outcome of these genetic tests and descriptions of the patients in whom genetic diagnoses were reached, as well as a brief review of the literature in HD phenocopies.
Methods DNA was analysed from 285 consecutive patients with HD phenocopy syndromes whose samples were referred for genetic testing to the Clinical Neurogenetics service of the National Hospital for Neurology and Neurosurgery, London. The service receives referrals from neurology and neurogenetics clinics across the United Kingdom, with a particular focus in London and south-east UK. The majority of referrals (206 of 285) were from experienced consultant neurologists and neurogeneticists within the National Hospital for Neurology and Neurosurgery, which also has a nationwide catchment with a focus on London and the south-east UK. Subjects were defined as HD phenocopies on the basis of a clinical presentation consistent with HD when assessed by a consultant neurologist or neurogeneticist and a negative test for the pathogenic CAG repeat expansion in the gene encoding huntingtin. Clinical information was obtained from the abstract accompanying the referral, from hospital records and by direct communication with referring clinicians. An autosomal dominant family history was not an absolute requirement because HD may arise de novo because of CAG repeat expansion, or appear to do so where the family history is unavailable, incomplete or inaccurate.
In this series of 285 patients with HD phenocopy syndromes—the largest investigated to date—8 patients (2.8%) were identified with genetic mutations. SCA17 was the most commonly identified disorder (5 cases) with HDL2, familial prion disease and Friedreich’s ataxia also identified (1 case each). The commonest neurogenetic diagnosis in this cohort was SCA17. This causes intellectual deterioration, cerebellar ataxia, epilepsy and chorea, in 100, 90, 50 and 20% of patients respectively.12 All 5 SCA17 patients we report here presented with chorea and falls and developed ataxia and cognitive impairment, but cerebellar atrophy was not a universal feature on brain imaging. Thus, HD phenocopy patients represent an atypical subset of SCA17 cases. Within a given pedigree, SCA17 HD phenocopy syndromes are relatively phenotypically homogeneous.23 SCA17 is caused by CAG-CAA expansions in the TATA-box binding protein which is an important transcription initiation factor. 24 This is of relevance to HD where transcriptional dysregulation occurs early in disease pathogenesis. 25 As well as being the largest HD phenocopy cohort studied to date, this study is the first time Friedreich’s ataxia (FA) has been described as an HD phenocopy