Global developmental delay, and Progressive cerebellar ataxia

Spinocerebellar ataxia type 21 (SCA21) is a very rare subtype of type I autosomal dominant cerebellar ataxia (ADCA type I; see this term). It is characterized by slowly progressive cerebellar ataxia, mild cognitive impairment, postural and/or resting tremor, bradykinesia, and rigidity.

SPINOCEREBELLAR ATAXIA TYPE 21 Is also known as sca21

• Intellectual disability
• Global developmental delay
• Ataxia
• Nystagmus
• Neoplasm

SOURCES: MESH OMIM ORPHANET MENDELIAN

AUTOSOMAL RECESSIVE ATAXIA DUE TO PEX10 DEFICIENCY Is also known as mild peroxismal disorder due to pex10 deficiency

• Global developmental delay
• Hyperreflexia
• Dysarthria
• Intellectual disability, mild
• Pes cavus

SOURCES: ORPHANET MENDELIAN

Spectrin-associated autosomal recessive cerebellar ataxia is a rare, genetic neurological disease, due to SPTBN2 mutations, characterized by global development delay in infancy, followed by childhood-onset gait ataxia with limb dysmetria and dysdiadochokinesia, mild to severe intellectual disability, development of cerebellar atrophy, and abnormal eye movements (including a convergent squint, hypometric saccades, jerky pursuit movements and incomplete range of movement).

SPECTRIN-ASSOCIATED AUTOSOMAL RECESSIVE CEREBELLAR ATAXIA Is also known as infantile-onset spinocerebellar ataxia-psychomotor delay syndrome|cerebellar ataxia, autosomal recessive, spectrin-associated, 1|ataxie spinocÉrÉbelleuse À dÉbut infantile avec retard psychomoteur|spectrin-associated autosomal recessive cerebellar ataxia

• Intellectual disability
• Global developmental delay
• Ataxia
• Nystagmus
• Strabismus

SOURCES: ORPHANET OMIM MENDELIAN

• Intellectual disability
• Global developmental delay
• Generalized hypotonia
• Hearing impairment
• Ataxia

SOURCES: OMIM MENDELIAN

Focal epilepsy with speech disorder is a childhood-onset seizure disorder with a highly variable phenotype. Seizures typically occur in the temporal lobe, or rolandic brain region, which affects speech and language, and electroencephalogram (EEG) characteristically shows centrotemporal spike-wave discharges. EEG abnormalities often occur during sleep and may manifest as continuous spike-wave discharges during slow-wave sleep (CSWS or CSWSS). FESD represents an electroclinical spectrum that ranges from severe early-onset seizures associated with delayed psychomotor development, persistent speech difficulties, and mental retardation to a more benign entity characterized by childhood onset of mild or asymptomatic seizures associated with transient speech difficulties followed by remission of seizures in adolescence and normal psychomotor development. There is incomplete penetrance and intrafamilial variability, even among family members who carry the same GRIN2A mutation (summary by Lesca et al., 2013; Lemke et al., 2013; Carvill et al., 2013).The disorder represented here encompasses several clinical entities, including Landau-Kleffner syndrome (LKS), epileptic encephalopathy with continuous spike and wave during slow-wave sleep (ECSWS; CSWSS), autosomal dominant rolandic epilepsy, mental retardation, and speech dyspraxia (ADRESD; RESDAD), and benign epilepsy with centrotemporal spikes (BECTS; see {117100}). LKS is classically described as a childhood-onset variant of epileptic aphasia. It is associated with EEG abnormalities occurring in the temporal lobe of the language-dominant hemisphere, even in the absence of overt clinical seizures. LKS is sometimes referred to as an 'acquired aphasia' because most affected children show normal psychomotor development until the onset of seizures, usually between 3 and 7 years, although some may have prior delayed development. A hallmark of the disorder is severe impairment in auditory language comprehension and speech. Some patients may also have persistent intellectual disability or behavioral abnormalities reminiscent of autism or attention deficit-hyperactivity disorder. EEG abnormalities typically include centrotemporal spikes suggestive of rolandic epilepsy or continuous spike and waves during slow-wave sleep. The presence of CSWS is associated with more widespread behavioral and cognitive regression than LKS, although the 2 disorders may be considered part of a spectrum. There is controversy about the precise definition of LKS and its relationship to CSWS that stems mainly from the phenotypic heterogeneity of the disorder (summary by Stefanatos, 2011).

EPILEPSY, FOCAL, WITH SPEECH DISORDER AND WITH OR WITHOUT MENTAL RETARDATION; FESD Is also known as aphasia, acquired, with epilepsy

• Intellectual disability
• Seizures
• Global developmental delay
• Generalized hypotonia
• Microcephaly

SOURCES: OMIM MENDELIAN

Sialic acid storage diseases are autosomal recessive neurodegenerative disorders that may present as a severe infantile form (ISSD) or as a slowly progressive adult form that is prevalent in Finland (Salla disease). The main symptoms are hypotonia, cerebellar ataxia, and mental retardation; visceromegaly and coarse features are also present in the infantile cases. Progressive cerebellar atrophy and dysmyelination have been documented by MRI. Enlarged lysosomes are seen on electron microscopic studies, and patients excrete large amounts of free sialic acid in the urine (Verheijen et al., 1999).

FREE SIALIC ACID STORAGE DISEASE, INFANTILE FORM Is also known as issd|sialuria, finnish type

• Intellectual disability
• Seizures
• Global developmental delay
• Generalized hypotonia
• Ataxia

SOURCES: ORPHANET OMIM MENDELIAN

Dysequilibrium syndrome (DES) is a non-progressive cerebellar disorder characterized by ataxia associated with an intellectual disability, delayed ambulation and cerebellar hypoplasia.

DYSEQUILIBRIUM SYNDROME Is also known as cerebellar ataxia-intellectual disability-dysequilibrium syndrome syndrome|cerebellar hypoplasia, vldlr-associated|non-progressive cerebellar ataxia-intellectual disability syndrome|cerebellar ataxia and mental retardation with or without quadrupedal loco

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

SOURCES: OMIM ORPHANET MENDELIAN

This syndrome is characterised by childhood-onset progressive ataxia and cerebellar atrophy.

AUTOSOMAL RECESSIVE ATAXIA DUE TO UBIQUINONE DEFICIENCY Is also known as arca2|autosomal recessive cerebellar ataxia type 2|spinocerebellar ataxia, autosomal recessive 9|scar9|autosomal recessive ataxia due to coenzyme q10 deficiency|autosomal recessive spinocerebellar ataxia type 9

• Intellectual disability
• Seizures
• Global developmental delay
• Generalized hypotonia
• Hearing impairment

SOURCES: MESH OMIM ORPHANET MENDELIAN

Spinocerebellar ataxia-7 (SCA7) is an autosomal dominant neurodegenerative disorder characterized by adult onset of progressive cerebellar ataxia associated with pigmental macular dystrophy. In her classification of ataxia, Harding (1982) referred to progressive cerebellar ataxia with pigmentary macular degeneration as type II ADCA (autosomal dominant cerebellar ataxia). The age at onset, degree of severity, and rate of progression vary among and within families. Associated neurologic signs, such as ophthalmoplegia, pyramidal or extrapyramidal signs, deep sensory loss, or dementia, are also variable. Genetic anticipation is observed and is greater in paternal than in maternal transmissions (Benomar et al., 1994; summary by David et al., 1996).For a general discussion of autosomal dominant spinocerebellar ataxia, see SCA1 (OMIM ).

SPINOCEREBELLAR ATAXIA 7; SCA7 Is also known as opca iii|opca with macular degeneration and external ophthalmoplegia|adca, type ii|olivopontocerebellar atrophy iii|opca3|opca with retinal degeneration|autosomal dominant cerebellar ataxia, type ii

• Global developmental delay
• Generalized hypotonia
• Ataxia
• Nystagmus
• Failure to thrive

SOURCES: OMIM MENDELIAN

Autosomal recessive spinocerebellar ataxia-21 is a neurologic disorder characterized by onset of cerebellar ataxia associated with cerebellar atrophy in early childhood. Affected individuals also have recurrent episodes of liver failure in the first decade, resulting in chronic liver fibrosis, as well as later onset of a peripheral neuropathy. Mild learning disabilities may also occur (summary by Schmidt et al., 2015).

ACUTE INFANTILE LIVER FAILURE-CEREBELLAR ATAXIA-PERIPHERAL SENSORY MOTOR NEUROPATHY SYNDROME Is also known as spinocerebellar ataxia, autosomal recessive 21, with hepatopathy|autosomal recessive spinocerebellar ataxia type 21|scar21

• Intellectual disability
• Global developmental delay
• Ataxia
• Muscle weakness
• Spasticity

SOURCES: ORPHANET OMIM MENDELIAN