Autosomal Recessive Diseases

Question 1

Ataxia Telangiectasia characteistcs

Answer 1

Ataxia in early childhood including chorea, myoclonus, and neuropathy.
Oculomotor apraxia
Telangiectases in eyes and on skin
Higher AGP protein
Weakened immune system (chronic lung infections)
Increased leukemia/lymphoma risk

Question 2

Chorea, myoclonus, neuropathy, oculomotor apraxia

Answer 2

Chorea - involuntary jerking
Myoclonus - muscle twitches
Neuropathy - disturbances in nerve function
Oculomotor apraxia - troulbe moving eyes side to side

Question 3

AFP

Answer 3

Alpha-fetoprotein

Question 4

Genetic basis of ataxia-telangiectasia

Answer 4

ATM gene mutation…codes for ATM involved in cell division and DNA repair…cells in brain that coordinate movement (cerebellum), particularly sensitive to loss of ATM….also prevent cells from responding to DNA damage = cancers

Question 5

PCD

Answer 5

Prumary ciliary dyskinesia - immotile cilia syndrome or Kartagener syndrome

Question 6

PCD associations

Answer 6

Neonatal respiratory distress
Chronic airway infection...leads to bronchiectasis 
Nasal congestion 
Chronic ear infection 
Situs inversus totalis 
Heterotaxy 
Most males are infertile

Question 7

Bronchiectasis

Answer 7

Result of chronic airway infection

Walls of bronchi are thicked from inflammation and infection…have exacerbations

Question 8

PCD genetic basis

Answer 8

Lots of different but all affect protein dynein…cytoskeletal motor protein that transports cargo on microtubules…DNAH5/DNAI1 account for majority of cases….lead to PCD impairment of dynein and transport and result in reduced motility of cilia…cilia are responsbiel for controlling asymmetry of internal organs and important in lung system where they clear mucous

Question 9

Oculocutaneous albinism characteristics

Answer 9

Fair skin/white hair 
Reduced eye pigmentation 
Vision problems 
Nystagmus 
Strabismus 
Photophobia 
Melanoma

Question 10

Strabismus

Answer 10

Misalignment of the eyes

Question 11

Type 1 Oculocutaneous albinism

Answer 11

White hair, very pale skin, and light-colored irises…mutation of TYR…codes for tyrosinase…rate limiting enzyme in making melanin from tyrosin

Question 12

Type 2 oculocutaneous albinism

Answer 12

Less severe than 1
creamy white colored…hair may be darker
Mutation of OCA2…codes for membrane protein that transports tyrosine as part of melaning synthesis

Question 13

Type 3 osculocutaneous albinism

Answer 13

Rufous oculocutaneous albinism whcih affects dark-skinned people…reddish hair and skin and hazel/brown irises…TYRP1 gene mutations

Question 14

Type 4 oculocutaneous albinism

Answer 14

Similar to type 2…mutation of SLC45A2…codes for transport protein in melanin synthesis

Question 15

Tay-Sachs disease early signs

Answer 15

Slowed development
Weak muscles
Ataxia
Exaggerated startle reactions

Question 16

Tay-sachs later signs

Answer 16

Seizures
Vision/hearing loss
Intellectual disability
Paralysis

Question 17

Genetic basis of Tay-Sachs

Answer 17

HEXA gene mutations…codes for beta-hexosaminidase A (lysosomal enzyme)…Mutations prevents from breaking down GM2 ganglioside…buildup destroys neurons in the brain and spinal cord