List of Ataxias:

1 Progressive Ataxias

1.1 Autosomal Dominant:

Spinocerebellar ataxia (SCA) types: SCA1, SCA2, SCA3, SCA4, SCA5, SCA6, SCA7, SCA8, SCA10, SCA11, SCA12, SCA13, SCA14, SCA15, SCA16, SCA17, SCA18, SCA19, SCA20, SCA21, SCA22, SCA23, SCA25, SCA26, SCA27, SCA28, SCA29, SCA30, SCA31, SCA32, SCA33, SCA34, SCA35, SCA36

DRPLA (Dentatorubropallidoluysian atrophy)

1.2 Autosomal Recessive:

1.2.A. Associated with spinocerebellar dysfunction, triplet repeat disorders:

FRDA (Friedreich's Ataxia), AVED (Ataxia with selective vitamin E deficiency), Abetalipoproteinemia, Hypobetalipoproteinemia [dominant with recessive features of Abetalipoproteinemia]

1.2.B. Associated with DNA Repair Defects:

AT (Ataxia Telangiectasia), AOA1 (Ataxia with oculomotor apraxia Type-1), AOA2 (Ataxia with oculomotor apraxia Type-2), XP (Xeroderma pigmentosum), CKN1 or CSA (Cockayne syndrome type-A), and CKN2 or CSB (Cockayne syndrome type B), SCAR1 (Autosomal Recessive Cerebellar Ataxia)               

1.2.C. Associated with Protein Translation and Folding Defects:

ARSACS (Autosomal recessive spastic ataxia of Charlevoix-Saguenay), 4H syndrome, VWM disease (Leukoencephalopathy with VWM [vanishing white matter])

1.2.D. Associated with Inherited Enzyme Defects:

1.3 Maternal inheritance Recessive:

1.4 Progressive Ataxias With Polymyoclonus and Epileptic Seizures:

Unverricht-Lundborg syndrome, Late infantile neuronal ceroid lipofuscinosis, Lafora body disease, and MERRF (Myoclonic epilepsy with ragged-red fibers, *"MERRF could be better defined as a myoclonic ataxia rather than a myoclonic epilepsy")

2 Episodic and Intermittent Ataxias

2.1 Episodic Ataxias

Episodic Ataxia (EA) types:  EA1, EA2, EA3, EA4 (also known as periodic vestibulocerebellar ataxia), EA5, EA6

2.2 Intermittent Ataxias Related to Enzyme Defects:

Maple syrup urine disease, Hartnup disease, Defects of mitochondrial fatty acid beta-oxidation, Pyruvate dehydrogenase deficiency, Pyruvate carboxylase deficiency, Late-onset urea cycle defects [Argininosuccinic acidemia, Carbamyl phosphate synthetase deficiency, Citrullinemia, Ornithine transcarbamoylase deficiency, Argininemia]

3 Non-Progressive Cerebellar Ataxias

**"The classification of nonprogressive ataxias is challenging. At the risk of oversimplification, the hereditary nonprogressive ataxias may be categorized as the following:

•          Pure congenital cerebellar ataxias
•          Cerebellar ataxias associated with posterior fossa malformations
•          Congenital ataxic syndromes
•          Ataxic syndromes without cerebellar malformations

The principal differential diagnosis needs to include metabolic and neurodegenerative conditions manifesting in early life discussed in this article. The suggested metabolic testing and neuroimaging studies can help distinguish this category from other hereditary conditions that are progressive in nature.

A long list of conditions is reported featuring ataxia in association with other clinical features. A few conditions such as Gillespie syndrome include 1 or 2 additional features (eg, mental retardation, partial aniridia), while other conditions such as Joubert syndrome (ie, hypotonia, hyperventilation, facial dysmorphism, retinal dystrophy, renal involvement) and COACH syndrome (ie, cerebellar hypoplasia, oligophrenia, ataxia, coloboma, hepatic fibrosis) feature malformations in multiple organ systems. Inheritance patterns are usually autosomal recessive or X linked depending on the syndrome. In the case of Joubert syndrome, evidence for genetic heterogeneity exists. Currently, mutations in 9 different genes are known to be associated with a Joubert syndrome phenotype."

4 X-Linked Ataxias

X-Linked Spinocerebellar ataxia (SCA) types:  SCAX1, SCAX2, SCAX3, SCAX4, SCAX5

Sources used for above tables:

Ataxia with Identified Genetic and Biochemical Defects - http://emedicine.medscape.com/article/1153370-overview by Author: Fredy J Revilla, MD Coauthor(s): Ramya Raghavan  (Co-op Student, University of Cincinnati); Additional Contributors: Cheryl R Greenberg (MD Professor), Mandar S Jog (MD Professor, Department of Neurology, University of Western Ontario); Asuri Prasad (MBBS, MD, FRCPE, FRCPC Associate Professor, Department of Pediatrics and Clinical Neurosciences, Faculty of Medicine, University of Western Ontario; Consulting Staff, Children's Hospital of Western Ontario); Chitra Prasad (MD, FRCPC, FCCMG, FACMG Director of Metabolic Services, Children's Hospital, London Health Sciences Centre; Associate Professor, Departments of Genetics, Metabolism and Pediatrics, University of Western Ontario School of Medicine, Canada)

Spinocerebellar ataxia From Wikipedia - http://en.wikipedia.org/wiki/Spinocerebellar_ataxia

Genetics Home Reference - http://ghr.nlm.nih.gov/condition/episodic-ataxia

Vestibulocerebellar syndrome From Wikipedia - http://en.wikipedia.org/wiki/Vestibulocerebellar_syndrome

Hereditary Ataxia Overview by Thomas D Bird, MD - http://www.ncbi.nlm.nih.gov/books/NBK1138/

ACAF/CAFA (Association canadiennes des ataxies familiales | Canadian Association for Familial Ataxias) - http://www.lacaf.org

The Jacques P.Tremblay Lab. - http://jptremblaylab.crchul.ulaval.ca/

Conference about the research project on Friedreich Ataxia given by Dr. Jacques P.Tremblay - http://www.youtube.com/watch?v=_NHdB1tAMnk

RQMO (Regroupement québécois des maladies orphelines) - http://www.rqmo.org/

ARSACS - http://www.ncbi.nlm.nih.gov/books/NBK1255/ by Sascha Vermeer, MD, PhD, Bart P van de Warrenburg, MD, PhD, and Erik-Jan Kamsteeg, PhD.

University of Minnesota Ataxia Center - http://www.ataxiacenter.umn.edu/aboutataxia/home.html

OMIM® (Online Mendelian Inheritance in Man®) sources for SCAX1 to SCAX5 - http://omim.org/entry/302500, http://omim.org/entry/302600, http://omim.org/entry/301790, http://omim.org/entry/301840, http://omim.org/entry/300703;

Phenotypic heterogeneity of the 8344A>G mtDNA “MERRF” mutation by Michelangelo Mancuso, MD, PhD; and various contributors. - http://www.neurology.org/content/early/2013/04/30/WNL.0b013e318294b44c.abstract