allele: a specific form of a gene (on one chromosome);
autosome/autosomal: an autosome is a non-sex chromosome, meaning it is one of the chromosmes that come in pairs;
autosomal dominant: an autosomal gene where the trait can be expressed even if only one copy of the gene
is the appropriate allele (i.e., the trait can be expressed if the individual is heterozygous);
autosomal recessive: an autosomal gene where the trait can be expressed only if both copies of the gene
are the appropriate allele (i.e., the trait can be expressed only if the individual is homozygous);
expressivity: refers to there being a range of phenotype variation among carriers (when penetrance is 100%);
familial: runs in families, making it likely there is a genetic/hereditary basis;
gene: the basic hereditary unit, consisting of a sequence of DNA at a specific location on a chromosome,
a gene contributes to phenotype/function of the individual;
genotype: the gentic code of an individual, e.g., which particular alleles/versions the two copies of a gene are;
heterozygous: the two copies of a gene are different alleles (versions), such an individual is termed a heterzygote;
homozygous: both copies of a gene are the same allele (version), such an individual is termed a homzygote;
penetrance: the probability that a carried genetic trait is expressed--i.e., the probability that the genotype
is reflected in the phenotype--penetrance can be complete (100%) or incomplete;
phenotype: the physical and biochemical makeup of an individual, which will have resulted from the interactions between
its (overall) genetic makeup and its environment--e.g., whether a mutation positive genotype manifests as clinical disease;