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Identical by descent (IBD):

When two individuals share an allele which was inherited from a common ancestor.


Iowa Institute of Human Genetics


Insertion/deletion variant

In frame deletion:

A deletion of a multiple of three nucleotides that does not alter the reading frame of the protein.

Informed consent:

A communication process during which one learns the risks, benefits, limitations, potential implications, possible results , and any necessary information about a test or research study so the individual can make an informed decision regarding their care or desire to participate in research. By giving permission to proceed with the test or to refuse the test, the individual acknowledges they understand the test and all of their questions have been answered.


To receive genetic material from parents.

Insertion (Ins):

The addition of genetic material ranging from a single nucleotide to a large DNA sequence or chromosome. The addition of the genetic material can result in an altered amino acid sequence thereby altering the protein sequence, or disrupt a chromosome segment.


The DNA sequence between genes in the human genome.


The non-coding portion of a gene separating the coding regions (exons). Intron nucleotides are initially transcribed into RNA but spliced out (removed) before translation into protein.

Intronic variant:

A nucleotide change in an intronic region which may alter splicing and result in a mature messenger RNA sequence with retained intron sequence.

Inversion (INV):

A chromosome alteration in which a segment of the chromosome is reversed. (end to end / order). A pericentric inversion is when the centromere is included (involves both chromosome arms). A paracentric inversion does not involve the centromere (just located on p or q arm).