Alopecia, also known as baldness, refers to hair loss in areas of skin that normally have hair. There are two forms: scarring and non-scarring. Symptoms depend on the type of hair loss, and can include patches of hair loss, thinning hair, or hair falling out. Dental infections have been linked to alopecia, with bald patches sometimes appearing in areas corresponding to tooth infections. Alopecia is classified as a multifactorial genetic trait influenced by multiple genes and environmental factors. Genome mapping has linked alopecia to several chromosomes, including linkage to chromosome 18 in one study.
2. A. Definition
ALOPECIA
Also known as âBaldness.â
Refers to hair loss in areas of skin
that normally have hair.
There are two forms of alopecia: scarring
and non-scarring.
âą Scarring
âą Non-scarring
4. B. SIGNS AND SYMPTOMS
ALOPECIA SYMPTOMS DEPEND ON THE TYPE OF HAIR LOSS. SOME OF
THE MORE COMMON SYMPTOMS INCLUDE:
Male-pattern baldness: Female-pattern baldness:
âąHair recedes âąHair thins over the entire head
âąHair falls out at the top of the head âąHair comes out when brushing
Fungal infections:
âąAffects men and women
âąPatches of hair loss
Alopecia areata:
âąBlack dots in the patches
âąRapid hair loss
âąItching
âąRound or oval patches of hair loss âąScaling
âąSometimes tiny hairs are visible in âąInflammation (such as redness)
the patches Stress-related:
âąFingernails and toenails with pits âąGradual shedding
âąHairs come out with gentle pulling
7. PRECAUTIONS
âą Patients with alopecia are advised to visit their dentists in
order to receive a careful examination of their oral health.
âą If you want to minimize your hair loss,
the two nutrients that you have to
make sure you have plenty of every
day. These nutrients are Vitamin A
and Vitamin B.
8. D. CLASSIFICATION OF THE DISEASE
MULTIFACTORIAL
Martinez-Mir et al. (2007) suggested that alopecia fits the paradigm of a complex or
multifactorial genetic trait based on several lines of evidence: its prevalence in the
population of approximately 2%; concordance in twins of 55% (Jackow et al., 1998);
a Gaussian distribution of severity; a 10-fold increased risk for first-degree relatives
of affected individuals; and the aggregation of affected individuals in families with no
clear mendelian pattern of inheritance.
Mapping
Linkage to Chromosome 18
In an effort to define a genetic basis of alopecia, Martinez-Mir et al. (2007) performed a genomewide
search for linkage to 20 families with 102 affected and 118 unaffected individuals from the United
States and Israel. The analysis revealed evidence of at least 4 susceptibility loci on chromosome 6, 10,
16, and 18 using several different statistical approaches. Fine-mapping analysis with additional families
yielded a maximum multipoint lod score of 3.93 on chromosome 18 at marker D18S967 (AA1), a 2-
point affected sib pair (ASP) lod score of 3.11 on chromosome 16 (AA2; 610753), several ASP lod
scores greater than 2.00 on chromosome 6q, and a haplotype-based relative risk lod of 2.00 on
chromosome 6p, in the major histocompatibility complex locus.