HUMAN TRAITS

PEDIGREE * CHART OF RELATIONSHIPS WITH A FAMILY; DETERMINES GENOTYPES OF TRAITS OF MEMBERS

Autosomal Recessive Diseases Inheritance when 2 parents who share a recessive gene for a disease pass this gene to an offspring. Usually, parents are heterozygous for this trait & are unaware of their potential for passing on this disease. Examples: Tay-Sachs Disease, Albinism, Cystic Fibrosis, PKU

RECESSIVE ALLELE DISORDERS 1. ALBINISM (aa) = NO SKIN PIGMENT

2. CYSTIC FIBROSIS – EXCESS LUNG MUCUS

3. PKU –HIGH PHENYLALANINE (AMINO ACID) IN TISSUES.

4. TAY-SACHS – HIGH LIPIDS IN BRAIN

AUTOSOMAL DOMINANT DISORDERS *the inheritance of a single copy of a defective gene that “over-rides” normal gene !

1. HUNTINGTON’S DISEASE – NEUROLOGICAL

CO-DOMINANT DISORDERS 1. SICKLE-CELL DISORDER – RED BLOOD CELLS