2 What are they?A disease that is caused by an abnormality in a person’s DNA.
3 Types of Disorders Single Gene Disorders Chromosomal Abnormalities A mutations causes the protein product to be altered or missingChromosomal AbnormalitiesEntire chromosomes, or large segments of them are missing, duplicated, or altered.Multi-factorial DisordersResult from mutations in multiple genes coupled with environmental causes
4 Single Gene Disorders Cystic Fibrosis Recessive disorderUsually helps move salt into & out of the cellWhen defective it causes a thick, sticky mucous to be madeCauses issues with digestive system & lungs
5 Single Gene Disorder Sickle Cell Anemia Recessive geneCauses red blood cells to be rigid & concaveThey are not able to transport oxygen very well (hemoglobin)Resistant to malaria
6 Single Gene Disorder Huntington’s Disease Dominant diseaseCauses brain cells to be destroyed that deal with movement, emotion, & thinking
7 Single Gene Disorder PKU Phenylketonuria (recessive)Codes for an enzyme in the liver that breaks down the amino acid phenylalanineCauses phenylalanine to build up in the blood which poisons brain cells (neurons)Can’t eat protein!
8 Chromosome Abnormalities Non-Disjunction Disorders When homologous chromosomes or chromatids do not separate during meiosisResults inMonosomy – only one copy of a chromosomeTrisomy – having 3 copies of a chromosome
9 Turner’s Syndrome Only affect females X (missing X) Female appearance InfertileDon’t mature
10 Klinefelter’s Syndrome Only affects malesXXY (extra X)Some female characteristicsVery little facial hairInfertile (don’t produce sperm)
11 Down Syndrome Trisomy of chromosome 21 Causes too much protein to be made, which causes problems
12 Sex-linked or X-linked Traits More genes can be carried on the X chromosome than the YGenes ONLY on X chromosomes are called “X-linked”Since there is only one allele, the phenotype of that allele is expressed in males