Achondroplasia

Dwarfism - Most common form

4th Chromosome

Protein FGFR3

80% of cases are mutations

3 copies of Chromosome 21

Phenotypic: small eyes/mouth, round face, single crease on hand.

Types: Nondisjunction (most common), Mosaicism (less extreme), Translocation (attaches to Chromosome 14, does not show in parent, will show in offspring if inherited)

Affects only girls.

Phenotypic: Only girls, cannot reproduce. 

Types: Monosomy (one X), Mosaicism (some cells XX some cells X), Y-Chromosome material (some Y genes located on the X-Chromosome)

Autosomal Recessive

C-T-T Deletion Chromosome 7

Phenotypic:  Salty skin, oftentimes cannot reproduce

Affects: Digestive system, lungs, reproductive tract

Chromosome 15

Autosomal Recessive

Usually die before age 5

Damage exists before birth

Uncontrolled bleeding

X-Linked Recessive

F8 coagulation or F9 coagulation

Extra X (ex: XXY, XXXY, XXXXY)

Male Only

Phenotypic: Delayed puberty

Less Testosterone

Recessive X-Linked

Males affected only

Muscle weakness, delayed intellectual ability

Chromosome 15 long arm

Autosomal Dominant

Phenotypic: Tall/Thin, nearsighted, detachment from retina, heart problems, WEAK AORTA

Protein FBN1 encodes for fibrillin-1: creates long structures that store growth hormones and release them at the wrong times.

Degeneration of nerve cells in brain

Duplication of CAG (30-40 duplications)

Protein is overused or overproduced. 

Genetic Anticipation (More duplication with each generation)

Depression/Suicide/Dance-like walk.  Worsens with age.

Autosomal Dominant

Chromosome 19

Worse when homozygous.

Phenotypic:  Cholesterol not taken care of properly, builds up LDL, leaves cholesterol deposits

Long Arm of X

X-Linked Dominant

Genetic Anticipation (CGG repeats)

The most common mental disability.

Fragile X Mental Retardation Protein

Angelmann Syndrome

(Puppet Syndrome)

Chromosome 15 gene UBE3A

Inherited through mother.

Affects nervous system. Most cases are mutation.  Bad sleeping habits. Normal life expectancy. Seizures.