Genotype-phenotype correlation is discussed in each GeneReview. The following are possible conclusions about genotype-phenotype correlations:

  • The strong correlation between genotype and phenotype allows the phenotype to be reliably predicted given the genotype.
  • The severity and specific clinical features of the phenotype cannot be reliably predicted due to the wide variability of phenotypic presentation between individuals with the identical genotype.
  • Genotype-phenotype correlation studies have not been done or are not practically possible due to the high number of different possible mutations.

Conversely, phenotype-genotype correlation asks the following question: Given a particular phenotype, what is the mostly likely genotype? In this instance, assessment of the phenotype directs the clinician/laboratory to test methods most appropriate for mutation detection.

Example: 22q11.2 deletion syndrome

Clinical features: Cardiac defects (particularly conotruncal defects), absent or abnormal thymus and/or parathyroid glands, cleft palate, characteristic facial features, speech problems, and developmental delay

Genotype-phenotype correlation: LOW A fetus found to have 22q11.2 deletion might have all of the associated clinical features, a few features, or just speech delay. The phenotype cannot be predicted based on the genotype.

Phenotype-genotype correlation: HIGH A child is born with a conotruncal cardiac defect and absent thymus. The likelihood of finding a 22q11.2 deletion is about 95%. The genotype can be reliably predicted on the basis of phenotype.

Updated: 1-23-04

Related Terms: genotype; phenotype

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From: Illustrated Glossary

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GeneReviews® [Internet].
Pagon RA, Adam MP, Ardinger HH, et al., editors.
Seattle (WA): University of Washington, Seattle; 1993-2014.
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