Structural Hair Abnormalities

Question 1

What gene is most commonly associated with Monilethrix?

Answer 1

KRT86 (hair cortex-specific keratin gene)

Monilethrix can also be associated with KRT81 and Dsg4.

Question 2

What is the inheritance pattern of Menkes kinky hair disease?

Answer 2

X-linked recessive

It is caused by mutations in the ATP7A gene affecting copper transport.

Question 3

What syndrome is characterized by pili torti and hearing loss?

Answer 3

Bjornstad syndrome

Bjornstad syndrome is associated with pili torti and hearing impairment.

Question 4

What is the genetic cause of Netherton’s syndrome?

Answer 4

SPINK5 gene (encodes serine protease inhibitor LEKTI)

Netherton’s syndrome presents with various hair abnormalities and ichthyosis.

Question 5

Which medication is most commonly associated with medication-induced hair shaft abnormalities?

Answer 5

Minoxidil

Other medications include phenytoin and cyclosporine.

Question 6

What is trichorrhexis invaginata also known as?

Answer 6

Bamboo hair

It is a characteristic finding in Netherton syndrome.

Question 7

What are the clinical findings of Bubble Hair?

Answer 7

Localized area of uneven, fragile hairs with light microscopy showing bubbles in hair shafts

This condition leads to hair fractures at bubble sites.

Question 8

What does pili torti look like under microscopy?

Answer 8

Flattened shaft and twisting of hair fiber on its own axis

It can be associated with various genetic conditions.

Question 9

Which syndrome includes basal cell carcinomas and milia as part of its features?

Answer 9

Bazex-Dupre-Christol syndrome

This syndrome also features pili torti and follicular atrophoderma.

Question 10

True or False: Hair abnormalities associated with Netherton’s syndrome arise in infancy.

Answer 10

True

The hair abnormalities manifest as short, sparse, and very fragile hair.

Question 11

Fill in the blank: Menkes syndrome is characterized by pili torti and _______.

Answer 11

trichorrhexis nodosa

It is also associated with growth failure and neurological abnormalities.

Question 12

What type of inheritance pattern does Crandall syndrome follow?

Answer 12

Autosomal recessive

Crandall syndrome includes features of Bjornstad syndrome plus hypogonadism.

Question 13

What are the common findings in hair abnormalities related to urea cycle defects?

Answer 13

Citrullinemia and argininosuccinic aciduria

These metabolic disorders can also affect hair structure.