Ambras Syndrome

What is Ambras Syndrome?

Ambras syndrome is a type congenital skin disease leads to unwarranted dense hair growth on the entire body, except in mucous membranes, soles, and palms. In Ambras syndrome , the hair growth is the typical type. The characteristic features include short, soft and fine hair growth in the facial zone and extended to ear and shoulder, which is also termed as vellus. The predominance of this disease is very rare.

Ambras syndrome is considered as a birth defect and cause of this disease involves chromosomal defect, including q (short) arm of the chromosome 8 has an abnormality. This genetic abnormality is inherited autosomal dominant pattern. ^{(1, 2)}

Symptoms

The classic feature of Ambras syndrome is hypertrichosis. Illustration of hypertrichosis of Ambras syndrome can be explained with the following features:

Excess Hair Growth in entire body

• Excessive hair growth in the entire body, including on the back, hand and face and even external ear also cover with light colored, fine dense hair. Though the soles, palms, and mucosa are not covered with hair growth.

Apart from the excessive hair growth following symptoms are also prominent, but some may or may have all the mentioned symptoms.

• Dysmorphic facial appearance, including triangular facial structure and uncouth facies, the wide distance between two eye orbits (hypertelorism), a prominent and broad nasal root, a hefty interalar space, encircle nasal tip, and anteverted nostrils
• Second degree of relation found with same common ancestral relation (consanguinity)
• In some cases, generalized gingival hyperplasia found in the intraoral examination. The included features are dislodgment of maxillary and mandibular anterior teeth with the elevated domed shaped palate and dental caries. ^{(2, 3, 5, 6)}

Causes

Hair growth in human is classified into three distinct cycles – lanugo, vellous and terminal hair. In fatal life cycle, hair growth is termed as lanugo. Soon after the nature of hair growth is vellous type. Vellous type hairs are mainly found in children on their face and arm. Terminal hair growth occurs in the scalp, eyelashes and eyebrows and pattern of hair is altered after puberty and alter according to aging. Vellous type hairs turn to terminal hair depending upon androgen hormonal balance.

The cause of Ambras syndrome is due to abnormal growth of vellous hairs occur in telogen phase of hair growth cycle. This type of abnormality of hirsutism usually occurs due to androgen hormonal imbalance and cause number of hair follicles on the surface of the skin. The cause of androgen hormonal imbalance or increase number of hair follicles in skin is unknown.

Baumeister et al. in 1993, first discover that 8q22-24 genetic alteration involves in the development of the Ambras syndrome, without involving hormonal abnormality. ^(4,5,6,7,8)

Diagnosis

The diagnosis of Ambras syndrome depends on upon hair analysis, which includes histology of hair and pattern of hair. Other than this, diagnosis of a hormonal abnormality, the genetic analysis also involves.

Type of Hair

The affected individual with Ambras syndrome has vellous type hair growth.

Pattern of hair

The pattern of hair in Ambras syndrome, include light colored silky nature hair. Nose, cheeks eyelids, external ears and shoulder cover with uniform dense hair. The hair length is measurable. But similar pattern hair growth is absent in scalp, eyelids or eyelash.

Hormonal abnormality

Differential diagnosis recommended that to check the androgen abnormality to exclude the reason, as Ambras syndrome is not associated with hormonal abnormality.

Genetic analysis

Genetic analysis is expensive, but according to the illustration of Baumeister et al. genetic analysis showed 8q22-24 genetic alteration. ^(5,6,7,8)

Complications

The most problematic complication associated with Ambras syndrome is hampering social life, which interferes in a personal relationship build up, low self-esteem. ⁽³⁾

Treatment

Ambras syndrome has no cure. The temporary management of Ambras syndrome includes frequent shaving, threading etc. Different laser or electric methods are available for permanent hair removal. Though the efficacy of application of this methods is unknown. It is suggested that underlying cause of treatment can reduce hair growth in affected patients. ^(2,3)

Prognosis

Usual genetic involvement related Ambras syndrome does not affect life span and patients have normal survival. In some cases, certain cancers also cause Ambras syndrome and that may reduce the lifespan of the patient. Therefore, detection of underlying reason is very crucial. ^(1,3)

References

1. Ambras syndrome, Genetic and Rare Diseases Information Center; https://rarediseases.info.nih.gov/diseases/8206/ambras-syndrome
2. Vinay Kumar Reddy Kundoor, Kotya Naik Maloth, Sunitha Kesidi, and Thakur Moni^, Ambras Syndrome with Gingival Hyperplasia: A Rare Entity; Int J Trichology. 2016 Apr-Jun; 8(2): 81–83; doi:  10.4103/0974-7753.188036; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4989393/
3. Babymed; http://www.babymed.com/fetal-malformations/ambras-syndrome
4. Balducci R, Toscano V, Tedeschi B, Mangiantini A, Toscano R, Galasso C, Cianfarani S, Boscherini B. A new case of Ambras syndrome associated with a paracentric inversion (8) (q12; q22) Clin Genet. 1998 Jun;53(6):466-8. PubMed
5. Paus R. Principles of hair cycle control. J Dermatol. 1998 Dec;25(12):793-802. PubMed
6. Dawber rp. Aetiology and pathophysiology of hair loss. Dermatologica. 1987;175 Suppl 2:23-8.PubMed
7. Macias-Flores MA, Garcia-Cruz D, Rivera H, Escobar-Lujan M, Melendrez-Vega A, Rivas-Campos D, Rodriguez-Collazo F, Moreno-Arellano I, Cantu JM. A new form of hypertrichosis inherited as an X-linked dominant trait. Hum Genet. 1984;66(1):66-70. PubMed
8. Baumeister FA. Diagnosis of Ambras syndrome: comments on complex cytogenetic rearrangement of chromosome 8q in a case of Ambras syndrome. Am J Med Genet. 2002 Apr 15;109(1):77-8.PubMed