Exam 3: Fragile X, Klinefelter and Turner Syndrome

Question 1

Is fragile x syndrome inherited or random?

Answer 1

Fragile X is an inherited disorder

It is second to DS in intellectual development disorders (IDD)

Question 2

What is fragile x syndrome?

Answer 2

Named because of a fragile site or break in the X chromosome

Question 3

What is the average age of diagnosis of fragile X?

Answer 3

36-42 months

Affects males and females

Question 4

What are clinical manifestations of fragile x?

Answer 4

Long and protruding ears
Long, thin face with prominent jaw
Epicanthal folds
High-arched palate
Increased head circumference
Large testes

Question 5

What are behavioral manifestations of fragile x?

Answer 5

Mild to severe IDD
Speech defects
Attention deficits
Autistic-like behaviors

Question 6

What is management of fragile x?

Answer 6

No cure
Managing symptoms, especially behavior-disorder symptoms
Pharmacolgic treatment: Ritalin, Dexedrine, Clonidine
Interdisciplinary treatment; team approach
Genetic evaluation of relatives, especially anyone with a family history of IDD with no diagnosis

Question 7

What is Klinefelter syndrome?

Answer 7

Males are born with an extra copy of the x chromosome

Males with Klinefelter syndrome have 47 chromosomes.

Genetic analysis shows XXY instead of XY.
Majority of cases have 47, the XXY constitution.

Variants are rare and include 48 (XXXY) or 49 (XXXXY) chromosomes.

Question 8

T or F: Older mothers are more at risk to have a child with Klinefelter syndrome than younger mothers?

Answer 8

True; often born to older mothers

Question 9

What is Turner syndrome?

Answer 9

Women with only one X chromosome.
Missing genetic material affects development before and after birth.
Complete loss of one X chromosome in about 50% of patients.
Sometimes chromosomal changes in only some cells.
Usually not inherited.
Error in cell division; similar to nondisjunction in Down syndrome.

Question 10

Does Klinefelter syndrome affect males or females or both?

Answer 10

Klinefelter affects males only

Question 11

Does Turner syndrome affect males or females or both?

Answer 11

Turner affects females only

Question 12

What is the most common sex chromosome abnormality?

Answer 12

XXY-Klinefelter syndrome

Question 13

When are men with Klinefelter syndrome typically diagnosed?

Answer 13

Puberty

-failure of adolescent secondary sex characteristic development

Question 14

What is seen with Klinefelter syndrome?

Answer 14

• microorchidism/small testes
• sterility/lack of sperm
• normal to borderline IQ
• diminished facial hair
• lack libido or sex drive

Question 15

What is important for PCPs to do when caring for a child with family history of intellectual disabilities of unknown etiology?

Answer 15

-do a genetic evaluation of the relatives

Question 16

In Klinefelter syndrome, physical and mental abnormalities associated with the syndrome increase as the number of ….

Answer 16

sex chromosomes increases: the more X chromosomes, the more symptoms

Question 17

With Turner syndrome, you would see a complete loss of X chromosome in about ____ percentage of cases:

Answer 17

50%

Question 18

What is it called when there are only chromosomal changes in some cells and not all?

Answer 18

Mosaicism

Question 19

Is Turner syndrome inherited?

Answer 19

Not usually

Question 20

Frequency of Turner Syndrome:

Answer 20

1 in 2500

Question 21

Frequency of Klinefelter Syndrome:

Answer 21

1 in 500 to 1 in 1,000

Question 22

Turner syndrome is a common cause of what?

Answer 22

Miscarriages

Question 23

Turner syndrome in newborns characteristics:

Answer 23

• webbing of neck
• lymphedema in hands and feet
• 1/3 to 1/2 with heart defect

Question 24

Cardiac abnormalities seen in Turner Syndrome:

Answer 24

• Aortic valve abnormality

- Coarctation of aorta

Question 25

What is the most common feature of Turner syndrome?

Answer 25

Short stature

Question 26

Characteristics of Turner Syndrome:

Answer 26

• Short stature
• loss of ovarian function (ovaries develop normally, egg cells die prematurely)
• require hormone therapy to undergo puberty
• most are infertile with the exception of a small percentage that can retain normal ovarian function through young adulthood

Question 27

Causes of short stature in Turner Syndrome:

Answer 27

Scoliosis & Kyphosis

Question 28

Women with Turner syndrome have an increased risk for this as they age:

Answer 28

Osteopenia, Osteoporosis

Question 29

What are approved treatments for Turner Syndrome?

Answer 29

• Growth hormone

- Estrogen replacement therapy starting at age 12

Question 30

IQ score in Fragile X:

Answer 30

30 to 55