Acrofrontofacionasal dysostosis is an extremely rare disorder, characterized by intellectual disability, short stature, hypertelorism, broad notched nasal tip, cleft lip/palate, postaxial camptobrachypolysyndactyly, fibular hypoplasia, and anomalies of foot structure.An association with mutations in the neuroblastoma amplified sequence gene (NBAS) has been reported. This gene is located on the short arm of chromosome 2. Mutations in this gene have been associated with the Short Stature, Optic Nerve Atrophy, and Pelger-Huet Anomaly syndrome and Infantile Liver Failure Syndrome. References

Richieri-Costa A, Colletto GM, Gollop TR, Masiero D (April 1985). "A previously undescribed autosomal recessive multiple congenital anomalies/mental retardation (MCA/MR) syndrome with fronto-nasal dysostosis, cleft lip/palate, limb hypoplasia, and postaxial poly-syndactyly: acro-fronto-facio-nasal dysostosis syndrome". Am. J. Med. Genet. 20 (4): 631–8. doi:10.1002/ajmg.1320200409. PMID 2986457. == External links ==
Contraindications
Combining the drug with pimozide or ergot alkaloids (such as ergotamine or methylergometrine) is contraindicated because these drugs are metabolized by the liver enzyme CYP3A4, and letermovir inhibits this enzyme. In people who also take ciclosporin, which increases letermovir concentrations in the body, combination with the cholesterol lowering drugs simvastatin and pitavastatin is also contraindicated. In Canada, this also applies to bosentan, lovastatin and rosuvastatin; and in the EU, to dabigatran, atorvastatin, and rosuvastatin. Adverse effects
Side effects from the use of letermovir are uncommon, but gastrointestinal symptoms such as gastritis and nausea may occur, as can dyspnea (difficulties breathing) and hepatitis. In general, side effects of the drug are comparable to those under placebo treatment. Overdose
In studies, giving the threefold therapeutic dose for 14 days resulted in no additional adverse effects. It is unknown whether the substance can be removed from the system by hemodialysis. Pharmacology
Mechanism of action
Letermovir is a viral terminase inhibitor. It specifically inhibits the CMV viral terminase complex which is encoded by the CMV genes UL56, UL51 and UL89. This inhibition has the effect of preventing cleavage of CMV DNA concatamers, resulting in long uncleaved DNA and noninfectious viral particles. Letermovir is only active against CMV and has no effect on other herpesviruses. Pharmacokinetics
Letermovir is quickly absorbed from the gut, reaching its highest concentrations in the blood plasma after 1.5 to 3 hours. Its bioavailability is estimated to be 37%. Ciclosporin increases this bioavailability to about 85%. When in the bloodstream, the substance is almost completely (98.2%) bound to plasma  proteins.