Causes
This condition is caused due to incomplete fusion of both sides of the nose during embryonic life.This anomaly is highly hereditary: autosomal dominant and autosomal recessive inheritance patterns have been observed in multiple families.If the bifid nose is accompanied by abnormalities of the anorectal and renal systems, it may be part of a different separate genetic disorder (which is characterized by overlapping toes, renal adysplasia and variable anorectal anomalies) that is caused by autosomal recessive mutations in the FREM1 gene. Treatment
Generally, sutures and rhinoplasty can be done in order to get rid of a bifid nose tip (though what surgery should be done depends on the severity of the cleft nose). Open W-shaped surgical incisions have also proven to be effective. Surgery is usually done before the age of 5. Prevalence
This birth anomaly affects less than 0.0008% of people worldwide, making it the most common midline craniofacial cleft.8% of people with bifid nose also have hypertelorism. Bifid nose as a hereditary trait
Two forms of inheritance pattern for bifid noses have been described: autosomal recessive and autosomal dominant. One case per inheritance pattern follows:

Autosomal dominant: Anyane-Yeboa et al. (1984) describes 5 women from a 3-generation American family. Karyotypes and skull X-rays done on the younger sisters gave normal results. Autosomal recessive: Boo-Chai et al. (1965) describes 3 siblings from a continental Indian family. History
This condition was first described in medical literature in 1939 by Esser et al. when they described 5 children (4 siblings and a male first-cousin of theirs) from a single family.
Mechanism of action
The causes of migraine are not clearly understood; however, the efficacy of naratriptans and other triptans is believed to be due to their activity as 5-HT (serotonin) agonists. Society and culture
In the United States, the Food and Drug Administration (FDA) approved naratriptan on February 11, 1998. It was covered by U.S. Patent no. 4997841; the FDA lists the patent as expiring on July 7, 2010.In July 2010, in the wake of the patent expiration, several drug manufacturers, including Roxane Labs, Sandoz and Teva Pharmaceuticals, announced that they were launching generic Naratriptan medications. The drug continued to be covered by European patent 0303507 in Germany, Spain, France and the United Kingdom through March 10, 2012, and by Australian patent 611469 in Australia through June 17, 2013. It had previously been covered by Canadian patent 1210968; but both Sandoz and Teva (formerly Novopharm) have offered generic equivalents in Canada since that patents expiration December 1, 2009.On December 23, 2014, in response to a request from Health Canada, importers in Canada agreed to quarantine the importation of health products, including generic Naratriptan manufactured for both Sandoz and Teva, from Dr. Reddys Laboratories in Srikakulam, India. Because Teva and Sandoz are the only approved suppliers of generic Naratriptan in Canada, the quarantine resulted in Naratriptan being placed on the Canadian drug shortage list.Following the Canadian quarantine, the United Arab Emirates Ministry of Health also imposed a similar quarantine. == References ==