More chromosomal

Question 1

Fragile X

Answer 1

Learning Difficulties
Long Face
Macro-Orchidism
Macrocephaly 
Large Ears

Question 2

Noonan Syndrome

Answer 2

Webbed Neck
Short Stature
Pectus Excavatum
pulmonary stenosis

Question 3

Pierre Robin

Answer 3

Micrognathia
Posterior Displacement of Tongue
cleft palate

Question 4

Where are the alpha globulin genes located?

What disease

Answer 4

Chromosome 16 (HBA1 and HBA2)
Alpha Thalassemia
- Autosomal recessive
- Decreased alpha globin production so less alpha globin chains.
- More beta chains in adults and excess gamma chains newborns
- beta chains result in unstable tetramer formation (Hb H)
- Four types depending on number of alleles effected (one-four)
-One and Two are relatively asymptomatic
- Three - Haemoglobin H disease. Two unstable haemoglobins are present in blood. Hemoglobin Barts (tetrameric y chains) and Hemoglobin H (tetrameric B chains)
- Four - Alpha thalassemia major. All haemoglobin is tetrameric y. Hydrops fetalis or BMT/ continuous chronic transfusions if survive

Question 5

HBB gene mutation on Chromosome 11

Answer 5

Beta thalassemia (Mutations in HBB gene on chromosome 11)

• Autosomal recessive
• Major - no beta chains produces so no haemoglobin A is assembles
• Intermedia - some haemoglobin A
• Minor - only one mutated beta globin chain