Iowa Institute of Human Genetics

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  • D

    dbSNP:

    NCBI database of genetic variation.

    del:

    See deletion.

    Deletion:

    The loss of genetic material, ranging from a single nucleotide to an entire chromosome.

    De novo mutation:

    A genetic alteration which arises in an individual that was not inherited from a parent, or was present for the first time in the egg or sperm from the parent.

    Depth of coverage (depth):

    The number of sequencing reads generated during massively parallel sequencing which align to and cover a specific genomic region or base pair. Higher depth of coverage generally increases confidence in variant calls.

    Dizygotic twins (DZ) (fraternal twins):

    Twins that developed from two separate fertilized eggs.

    DNA:

    Deoxyribonucleic acid

    Dominant:

    A characteristic, trait, or disorder which is phenotypically expressed when only one variant allele is present.

    Dominant negative:

    A mutation which results in an altered protein which interferes with the normal wild-type protein product, and may result in a novel protein function. These types of mutations may be more deleterious than a mutation which results in a premature stop or null allele when polymeric molecules are involved.

    Double heterozygote:

    When an individual is heterozygous at two different loci (which results in a disease).

    dup:

    See duplication.

    Duplication:

    An additional copy (gain) of genetic material, ranging from a single nucleotide to an entire chromosome.

    DZ:

    See dizygotic twins.