What are the other Names for this Condition? (Also known as/Synonyms)

• Beaded Hair
• Moniliform Hair Syndrome
• Nodose Hair

What is Monilethrix? (Definition/Background Information)

• Monilethrix is an uncommon genetic hair disorder resulting in “Beaded Hair”. It is also characterized by the presence of slow-growing brittle hair and patchy hair loss. The loss is from broken hair shafts, and not from loss or disease of the follicles
• The onset of Monilethrix is mostly noted following the birth of the child. The condition can result in severe emotional stress and cosmetic concerns apart from systemic symptoms, including rarely, intellectual impairment
• A treatment of Monilethrix involves topical agents and systemic medications. The prognosis depends on its severity, although in many cases, the condition may last a lifetime

Who gets Monilethrix? (Age and Sex Distribution)

• Monilethrix is a rare congenital disorder. However, the presentation of symptoms may occur any time after birth. The condition is usually apparent within the first few months of birth
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Monilethrix? (Predisposing Factors)

• A positive family history may be an important risk factor, since Monilethrix can be inherited
• Currently, no other risk factors have been clearly identified for the condition

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Monilethrix? (Etiology)

Monilethrix is a genetic disorder that is caused by mutations in the following genes:

• KRT81 gene
• KRT83 gene
• KRT86 gene
• DSG4 gene

The condition is inherited in an autosomal dominant manner, when KRT81, KRT83, or KRT86 is involved. However, when the DSG4 gene is involved, the condition is transmitted in an autosomal recessive manner.

Autosomal dominant: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly function gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition, or pass it on to their offspring.

Autosomal recessive: Autosomal recessive conditions are traits or disorders that occur when two copies of an abnormal gene have been inherited on a non-sex chromosome. If both parents have an autosomal recessive condition, there is a 100% likelihood of passing on the mutated genes to their children. If, however, only one mutant copy of the gene is inherited, the individual will be a carrier of the condition, but will not be present with any symptoms. Children born to two carriers, have a 25% chance of being homozygous dominant (unaffected), a 50% chance of being heterozygous (carrier), and a 25% chance of being homozygous recessive (affected).

What are the Signs and Symptoms of Monilethrix?

The signs and symptoms of Monilethrix may vary from one individual to another and may be mild or severe. It may include:

• Characteristic beaded appearance of hair - the hair appears like a string of beads
• Hair abnormalities that may include thin hair, brittle hair, slow-growing hair, patchiness on scalp, and hair loss. The entire scalp may be affected
• Involvement of hair at other body locations such as the eyebrows and eyelashes, armpits, hair on the arms, legs, and body, and pubic hair
• Nail abnormalities of the fingers and toes in some cases
• Follicular hyperkeratosis
• Skin lesions in the form of small bumps on the neck and arms
• Other systemic signs and symptoms may be noted

How is Monilethrix Diagnosed?

Monilethrix is diagnosed on the basis of the following information:

• Physical examination of the individual and medical history evaluation; a visual examination of the hair may help the healthcare provider suspect the condition
• Dermoscopy: Dermoscopy is a diagnostic tool where a dermatologist examines the skin using a special magnified lens
• Wood’s lamp examination: In this procedure, the healthcare provider examines the skin using ultraviolet light. It is performed to examine the change in skin pigmentation
• Trichoscopy (microscopic hair evaluation): Monilethrix hairs under low power magnification show a pattern of repeating normal diameter hair with a slow taper to narrow, then back to normal, followed by narrowing, and so on
• Skin biopsy, if necessary: A skin biopsy is performed and sent to a laboratory for a pathological examination. The pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis
• Molecular genetic testing, to identify the causative gene

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Monilethrix?

The complications of Monilethrix depends on the severity of the condition. It may include:

• Severe emotional stress due to cosmetic concerns
• Eye defects
• In some cases, intellectual impairment
• Treatment challenges

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Monilethrix Treated?

There is no cure for Monilethrix since it is a genetic condition. The treatment is usually given to manage the signs and symptoms. The healthcare provider may consider the following measures:

• Application of topical minoxidil
• Oral medication such as acitretin
• Conventional treatments such as vitamin supplementation, corticosteroid therapy, and hormonal medications are not known to be effective
• Avoidance of trauma that may include hair pulling, sun exposure, or damage from wind, use of hair cosmetics, etc. is advised

How can Monilethrix be Prevented?

Currently, Monilethrix may not be preventable since it is a genetic disorder.

• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

What is the Prognosis of Monilethrix? (Outcomes/Resolutions)

• The prognosis of Monilethrix is dependent upon the severity of the signs and symptoms and associated complications, if any. A spontaneous improvement is noted in a few cases, typically during puberty or pregnancy
• Individuals with mild conditions have better prognosis than those with severe symptoms and complications. Typically, the prognosis may be assessed on a case-by-case basis

Additional and Relevant Useful Information for Monilethrix:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/healthy-living/skin-disorders/