Dysarthria, and Ventriculomegaly

Megalencephalic leukoencephalopathy with subcortical cysts-2A is an autosomal recessive neurodegenerative disorder characterized by infantile-onset macrocephaly and later onset of motor deterioration, with ataxia and spasticity, seizures, and cognitive decline of variable severity. Brain MRI shows typical white matter abnormalities, including swelling of the cerebral white matter and subcortical cysts, in all stages of the disease (summary by Lopez-Hernandez et al., 2011).Heterozygous mutations in the HEPACAM gene can cause a similar, but less severe disorder that shows improvement of MRI changes with age (MLC2B ).

• Intellectual disability
• Seizures
• Ataxia
• Spasticity
• Motor delay

SOURCES: OMIM MENDELIAN

Autosomal recessive congenital cerebellar ataxia due to MGLUR1 deficiency is a rare, genetic, slowly progressive neurodegenerative disease resulting from MGLUR1 deficiency characterized by global developmental delay (beginning in infancy), mild to severe intellectual deficit with poor or absent speech, moderate to severe stance and gait ataxia, pyramidal signs (e.g. hyperreflexia) and mild dysdiadochokinesia, dysmetria, tremors, and/or dysarthria. Oculomotor signs, such as nystagmus, strabismus, ptosis and hypometric saccades, may also be associated. Brain imaging reveals progressive, generalized, moderate to severe cerebellar atrophy, inferior vermian hypoplasia, and/or constitutionally small brain.

AUTOSOMAL RECESSIVE CONGENITAL CEREBELLAR ATAXIA DUE TO MGLUR1 DEFICIENCY Is also known as autosomal recessive spinocerebellar ataxia type 13|scar13|autosomal recessive congenital cerebellar ataxia due to metabotropic glutamate receptor 1 deficiency

• Intellectual disability
• Seizures
• Global developmental delay
• Short stature
• Generalized hypotonia

SOURCES: ORPHANET OMIM MENDELIAN

HUNTINGTON DISEASE-LIKE 1 Is also known as early-onset prion disease with prominent psychiatric features|hln1|prion disease, early-onset, with prominent psychiatric features|hdl1|huntington-like neurodegenerative disorder 1|huntington-like neurodegenerative disorder, autosomal dominant

• Seizures
• Generalized hypotonia
• Ataxia
• Nystagmus
• Cognitive impairment

SOURCES: MESH OMIM ORPHANET MENDELIAN

Autosomal recessive spastic paraplegia type 75 is a rare, complex hereditary spastic paraplegia characterized by an early onset and slow progression of spastic paraplegia associated with cerebellar signs, nystagmus, peripheral neuropathy, extensor plantar responses and borderline to mild intellectual disability. Additional features of hypo- or areflexia, mild upper limb involvement and significant visual impairment (optic atrophy, vision loss, astigmatism) have been reported.

AUTOSOMAL RECESSIVE SPASTIC PARAPLEGIA TYPE 75 Is also known as spg75

• Intellectual disability
• Global developmental delay
• Generalized hypotonia
• Nystagmus
• Spasticity

SOURCES: OMIM ORPHANET MENDELIAN

ATAXIA-TELANGIECTASIA-LIKE DISORDER Is also known as atld

• Short stature
• Generalized hypotonia
• Ataxia
• Delayed speech and language development
• Dysarthria

SOURCES: ORPHANET MENDELIAN

• Intellectual disability
• Seizures
• Global developmental delay
• Short stature
• Generalized hypotonia

SOURCES: OMIM MENDELIAN

The autosomal dominant cerebellar degenerative disorders are generally referred to as 'spinocerebellar ataxias,' (SCAs) even though 'spinocerebellar' is a hybrid term, referring to both clinical signs and neuroanatomical regions (Margolis, 2003). Neuropathologists have defined SCAs as cerebellar ataxias with variable involvement of the brainstem and spinal cord, and the clinical features of the disorders are caused by degeneration of the cerebellum and its afferent and efferent connections, which involve the brainstem and spinal cord (Schols et al., 2004; Taroni and DiDonato, 2004).Historically, Harding (1982) proposed a clinical classification for autosomal dominant cerebellar ataxias (ADCAs). ADCA I was characterized by cerebellar ataxia in combination with various associated neurologic features, such as ophthalmoplegia, pyramidal and extrapyramidal signs, peripheral neuropathy, and dementia, among others. ADCA II was characterized by the cerebellar ataxia, associated neurologic features, and the additional findings of macular and retinal degeneration. ADCA III was a pure form of late-onset cerebellar ataxia without additional features. SCA1, SCA2 (OMIM ), and SCA3, or Machado-Joseph disease (OMIM ), are considered to be forms of ADCA I. These 3 disorders are characterized at the molecular level by CAG repeat expansions on 6p24-p23, 12q24.1, and 14q32.1, respectively. SCA7 (OMIM ), caused by a CAG repeat expansion in the ATXN7 gene (OMIM ) on chromosome 3p13-p12, is a form of ADCA II. SCA5 (OMIM ), SCA31 (OMIM ), SCA6 (OMIM ), and SCA11 (OMIM ) are associated with phenotypes most suggestive of ADCA III. However, Schelhaas et al. (2000) noted that there is significant phenotypic overlap between different forms of SCA as well as significant phenotypic variability within each subtype.Classic reviews of olivopontocerebellar atrophies and of inherited ataxias in general include those of Konigsmark and Weiner (1970), who identified 5 types of olivopontocerebellar atrophy, Berciano (1982), Harding (1993), Schelhaas et al. (2000), and Margolis (2003).

SPINOCEREBELLAR ATAXIA 1; SCA1 Is also known as opca i|opca1|opca4|olivopontocerebellar atrophy i|spinocerebellar atrophy i|opca iv|menzel type opca|olivopontocerebellar atrophy iv|cerebelloparenchymal disorder i|schut-haymaker type opca|cpd1

• Generalized hypotonia
• Ataxia
• Nystagmus
• Muscular hypotonia
• Spasticity

SOURCES: OMIM MENDELIAN

Spastic paraplegia-47 is an autosomal recessive neurodegenerative disorder characterized by neonatal hypotonia that progresses to hypertonia and spasticity and severe mental retardation with poor or absent speech development (summary by Abou Jamra et al., 2011).

SPASTIC PARAPLEGIA 47, AUTOSOMAL RECESSIVE; SPG47 Is also known as cpsq5, formerly|cerebral palsy, spastic quadriplegic, 5, formerly

• Intellectual disability
• Seizures
• Global developmental delay
• Short stature
• Generalized hypotonia

SOURCES: OMIM MENDELIAN

Frontotemporal dementia (FTD) refers to a clinical manifestation of the pathologic finding of frontotemporal lobar degeneration (FTLD). FTD, the most common subtype of FTLD, is a behavioral variant characterized by changes in social and personal conduct with loss of volition, executive dysfunction, loss of abstract thought, and decreased speech output. A second clinical subtype of FTLD is 'semantic dementia,' characterized by specific loss of comprehension of language and impaired facial and object recognition. A third clinical subtype of FTLD is 'primary progressive aphasia' (PPA), characterized by a reduction in speech production, speech errors, and word retrieval difficulties resulting in mutism and an inability to communicate. All subtypes have relative preservation of memory, at least in the early stages. FTLD is often associated with parkinsonism or motor neuron disease (MND) resembling amyotrophic lateral sclerosis (ALS ) (reviews by Tolnay and Probst, 2002 and Mackenzie and Rademakers, 2007). {30,31:Mackenzie et al. (2009, 2010)} provided a classification of FTLD subtypes according to the neuropathologic findings (see PATHOGENESIS below). Clinical Variability of TauopathiesTauopathies comprise a clinically variable group of neurodegenerative diseases characterized neuropathologically by accumulation of abnormal MAPT-positive inclusions in nerve and/or glial cells. In addition to frontotemporal dementia, semantic dementia, and PPA, different clinical syndromes with overlapping features have been described, leading to confusion in the terminology (Tolnay and Probst, 2002). Other terms used historically include parkinsonism and dementia with pallidopontonigral degeneration (PPND) (Wszolek et al., 1992); disinhibition-dementia-parkinsonism-amyotrophy complex (DDPAC) (Lynch et al., 1994); frontotemporal dementia with parkinsonism (FLDEM) (Yamaoka et al., 1996); and multiple system tauopathy with presenile dementia (MSTD) (Spillantini et al., 1997). These disorders are characterized by variable degrees of frontal lobe dementia, parkinsonism, motor neuron disease, and amyotrophy.Other neurodegenerative associated with mutations in the MAPT gene include Pick disease (OMIM ) and progressive supranuclear palsy (PSP ),Inherited neurodegenerative tauopathies linked to chromosome 17 and caused by mutation in the MAPT gene have also been collectively termed 'FTDP17' (Lee et al., 2001).Kertesz (2003) suggested the term 'Pick complex' to represent the overlapping syndromes of FTD, primary progressive aphasia (PPA), corticobasal degeneration (CBD), PSP, and FTD with motor neuron disease. He noted that frontotemporal dementia may also be referred to as 'clinical Pick disease' and that the term 'Pick disease' should be restricted to the pathologic finding of Pick bodies. Genetic Heterogeneity of Frontotemporal Lobar DegenerationMutations in several different genes can cause frontotemporal dementia and frontotemporal lobar degeneration, with or without motor neuron disease. See FTLD with TDP43 inclusions (OMIM ), caused by mutation in the GRN gene (OMIM ) on chromosome 17q21; FTLD mapping to chromosome 3 (OMIM ), caused by mutation in the CHMP2B gene (OMIM ); inclusion body myopathy with Paget disease and FTD (IBMPFD ), caused by mutation in the VCP gene (OMIM ) on chromosome 9p13; ALS6 (OMIM ), caused by mutation in the FUS gene (OMIM ) on 16p11; ALS10 (OMIM ), caused by mutation in the TARDBP gene (OMIM ) on 1p36; and FTDALS (OMIM ), caused by mutation in the C9ORF72 gene (OMIM ) on 9p.In 1 family with FTD, a mutation was identified in the presenilin-1 gene (PSEN1 ) on chromosome 14, which is usually associated with a familial form of early-onset Alzheimer disease (AD3 ).

FRONTOTEMPORAL DEMENTIA; FTD Is also known as mstd|frontotemporal dementia with parkinsonism|ftld with tau inclusions|ddpac|ftdp17|wilhelmsen-lynch disease|pallidopontonigral degeneration|frontotemporal lobar degeneration with tau inclusions|frontotemporal lobe dementia|disinhibition-dementia-parkins

• Hyperreflexia
• Dysarthria
• Skeletal muscle atrophy
• Tremor
• Dysphagia

SOURCES: OMIM ORPHANET MENDELIAN

Machado-Joseph disease type 1 is a rare, usually severe subtype of Machado-Joseph disease (SCA3/MJD, see this term) characterized by the presence of marked pyramidal and extrapyramidal signs.

MACHADO-JOSEPH DISEASE TYPE 1 Is also known as spinocerebellar ataxia type 3, joseph type|sca3, joseph type

• Spasticity
• Delayed speech and language development
• Peripheral neuropathy
• Hyperreflexia
• Dysarthria

SOURCES: ORPHANET MENDELIAN