Frequency of Inherited Disorders Database ©

Institute of Medical Genetics


Structure of FIDD and Search Procedure

FIDD has been structured systematically using the following fields (Huntington disease is provided as an example) :

Field Description Example
Condition Includes synonyms and sub-types Huntington disease
OMIM number May be multiple 143100
Mode of inheritance Autosomal dominant, recessive, X-linked recessive or mitochondrial Autosomal dominant
Population studied Geographic origin, region, sub-region and ethnic background, if available UK (Wales, South & Mid Glamorgan)
Cases Number of patients reported 79
Population size Actual number, when recorded 939,300
Time period of study The specific date or time period of assessment 1988
Prevalence/ Incidence§ Listed separately for different studies, as well as overall estimate when feasible; recorded as 1:X Prevalence 1:11,905
Main body systems involved May be multiple Neurological/neuromuscular system
Source of data Primary reference source MacMillan JC, Harper PS. Single gene neurological disorders in South Wales; an epidemiological study. Ann. Neurol. 1991; 30: 411-414.
Comments Unstructured text; may point to limitations or special features of the study Exhaustive ascertainment
  • Prevalence is defined as the number of cases observed either at a particular time (point prevalence) or during a given time period (period prevalence). Incidence is defined as the number of cases newly arising in a population during a specified period, divided by the size of the population at risk during the time period in which cases were collected (Vetter N, Mathews I (Eds). Epidemiology and Public Health. London: Churchill Livingstone, 1999.)
  • Disorders listed in FIDD are grouped by main body system affected:
    • Cardiac
    • Endocrine
    • Eye
    • Gastrointestinal
    • Haematological
    • Mental
    • Metabolic
    • Neurological and neuromuscular
    • Psychiatric
    • Renal
    • Respiratory
    • Skeletal
    • Skin and Miscellaneous
  • FIDD may be searched by:
    • Main Body Syststrong Involved (as specified above)
    • Name of Inherited Disease State
    • OMIM Number
    • Population Studied
  • A wildcard (*) may be used as an aid to searching. Thus "haem*" locates "hereditary haemorrhagic telangiectasia", "haemophilia" and "haemochromatosis" among others. A maximum of 40 entries will be returned.