Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- Part I Basic aspects of neurodegeneration
- Part II Neuroimaging in neurodegeneration
- Part III Therapeutic approaches in neurodegeneration
- Normal aging
- Part IV Alzheimer's disease
- Part VI Other Dementias
- Part VII Parkinson's and related movement disorders
- Part VIII Cerebellar degenerations
- Part IX Motor neuron diseases
- 50 An approach to the patient with motor neuron dysfunction
- 51 The genetics of amyotrophic lateral sclerosis
- 52 Current and potential therapeutics in motor neuron diseases
- 53 The hereditary spastic paraplegias
- 54 Spinal and bulbar muscular atrophy (Kennedy's disease): a sex-limited, polyglutamine repeat expansion disorder
- 55 Spinal muscular atrophies
- 56 Western Pacific ALS/parkinsonism–dementia complex
- Part X Other neurodegenerative diseases
- Index
- References
51 - The genetics of amyotrophic lateral sclerosis
from Part IX - Motor neuron diseases
Published online by Cambridge University Press: 04 August 2010
- Frontmatter
- Contents
- List of contributors
- Preface
- Part I Basic aspects of neurodegeneration
- Part II Neuroimaging in neurodegeneration
- Part III Therapeutic approaches in neurodegeneration
- Normal aging
- Part IV Alzheimer's disease
- Part VI Other Dementias
- Part VII Parkinson's and related movement disorders
- Part VIII Cerebellar degenerations
- Part IX Motor neuron diseases
- 50 An approach to the patient with motor neuron dysfunction
- 51 The genetics of amyotrophic lateral sclerosis
- 52 Current and potential therapeutics in motor neuron diseases
- 53 The hereditary spastic paraplegias
- 54 Spinal and bulbar muscular atrophy (Kennedy's disease): a sex-limited, polyglutamine repeat expansion disorder
- 55 Spinal muscular atrophies
- 56 Western Pacific ALS/parkinsonism–dementia complex
- Part X Other neurodegenerative diseases
- Index
- References
Summary
Models of inheritance
The genetics of a disease such as amyotrophic lateral sclerosis (ALS) require some flexibility in thinking about familiality compared with the genetics of isolated cases. About 10% of the time, an individual who develops ALS also has first-degree relatives who have been affected. For the remainder, the disease is said to be sporadic, but detailed investigation of the family tree may occasionally reveal that cousins or other more distant relatives have been affected. ALS can therefore be seen as a disease with an inheritance pattern that lies on a continuum from sporadic disease, to familial clustering to clear Mendelian familiality. For simplicity we have maintained the conventional separation of familial and sporadic disease, but as will become obvious, this distinction is largely artificial.
Familial ALS and the first descriptions
The concepts of genetics were coming into being at about the same time as the earliest descriptions of motor neuron diseases. Mendel presented his classic paper in 1865 (Mendel, 1865) in which he described his famous sweet pea hybridization experiments. He did not use the term gene or genetic to describe the heritable units but called them “formative elements.” Cambridge Professor of Biology William Bateson coined the term “genetics” (from the Greek “to generate”) in 1905 when applying for a university chair in a letter to the Cambridge zoologist, Adam Sedgwick. He wrote, “Such a word is badly wanted and if it were desirable to coin one, Genetics might do.”
- Type
- Chapter
- Information
- Neurodegenerative DiseasesNeurobiology, Pathogenesis and Therapeutics, pp. 758 - 771Publisher: Cambridge University PressPrint publication year: 2005