Module 3 Human Sex anomalies and Inborn Errors in Metabolism

Question 1

(47,XXX)
* incidence: 1 in 1000 female births
* above average stature
* normal phenotype
* most have learning disabilities
* behavior problems common
* many never diagnosed

Answer 1

Trisomy X

Question 2

(47,XXY)
* 1:1000 male births
* tall stature
* gynecomastia
* hypogonadism
* infertility
* learning disabilities
* problems with socialization
* many never diagnosed

Answer 2

Klinefelter Syndrome

Question 3

(47, XYY)
* 1/1000 newborn males
* tall stature
* most phenotypically normal
* normal IQ but 50% have learning disabilities (language and speech)
* many never diagnosed

Answer 3

Jacob Syndrome

Question 4

results when one normal X chromosome is present in a female’s cells and the other sex chromosome is missing or structurally altered

Answer 4

Turner syndrome

Question 5

– due to errors in cell division during early fetal development;
chromosomal change in only some of the cells

Answer 5

Mosaicism

Question 6

is an inherited disorder that increases the levels of a substance called phenylalanine in the blood. Phenylalanine is a building block of proteins (an amino acid) that is obtained through the diet. It is found in all proteins and in some artificial sweeteners.

PAH gene

Answer 6

Phenylketonuria (PKU)

Question 7

is an autosomal recessive inherited disorder in which the body is unable to process certain protein building blocks (amino acids)
properly.

BCKDHA gene, BCKDHB gene, DBT gene

Answer 7

Maple Syrup Urine Disease
(MSUD)

Question 8

• Galactose-1-phosphate uridyl transferase (GALT) is either missing or not working properly.
• also known as type I, is the most common and most severe form of the condition.

Answer 8

Classic galactosemia (GALT deficiency)

Question 9

e is due to lactase deficiency.

Answer 9

Lactose intolerance