basic definitions

1. HEREDITARY
Capable of passing naturally from parents to offspring through genes
CONGENITAL DISORDER
It is a condition existing at or before birth regardless of cause
CONGENITAL
It relates to a condition present at birth, whether inherited or caused by the
environment especially uterine environment
MUTATION
It is a relatively permanent change in hereditary material that involves either a
change in chromosome structure or number (as in translocation, deletion,
duplication, or polyploidy) or a change in the nucleotide sequence of a
gene's codons (as in frameshift or missense errors) and that occurs either in germ
cells or in somatic cells but with only those in germ cells being capable of
perpetuation by sexual reproduction
FAMILIAL
A condition that tends to occur more often in family members than is expected by
chance alone.

2. DELETION
It is a mutation (a genetic aberration) in which a part of a chromosome or a sequence
of DNA is lost during DNA replication
TRANSLOCATION
It is a chromosome abnormality caused by rearrangement of parts between
nonhomologous chromosomes
FRAMESHIFT
is a genetic mutationcaused by iindels (insertions ordeletions) of a number
of nucleotides in a DNA sequence that is not divisible by three
MOSAICISM
Mosaicism describes the presence of two or more populations of cells with
different genotypesin one individual, who has developed from a single fertilized egg