Bosma Arhinia Microphthalmia Syndrome

Clinical Characteristics

Ocular Features:

Microphthalmia or clinical anophthalmia are usually present. Iris colobomas are frequent features. Occluded or absent nasolacrimal ducts have been reported.

Systemic Features:

Arhina with anosmia is the most striking feature but it is usually accompanied by midface hypoplasia, a highly arched (or cleft) palate, and preauricular pits. The nasal bones along with the cribriform plate, and other septal structures may be missing. Maxillary and paranasal sinuses, together with the olfactory bulbs are often absent. Intelligence is usually normal.

Choanal atresia is often present. Hypogonadotropic hypogonadism with micropenis and cryptorchidism is an important feature in males. Females may experience pubertal delay with menarche anomalies.

Genetics

Heterozygous mutations in the SMCHD1 [1] gene (18p11) are responsible for this disorder. There is considerable clinical heterogeneity with many carriers having only minor manifestations.

Treatment

Treatment Options:

No treatment for the general disorder has been described.

References

Article Title:

De novo mutations in SMCHD1 cause Bosma arhinia microphthalmia syndrome and abrogate nasal development [2]

Gordon CT, Xue S, Yigit G, Filali H, Chen K, Rosin N, Yoshiura KI, Oufadem M, Beck TJ, McGowan R, Magee AC, Altmuller J, Dion C, Thiele H, Gurzau AD, Nurnberg P, Meschede D, Muhlbauer W, Okamoto N, Varghese V, Irving R, Sigaudy S, Williams D, Ahmed SF, Bonnard C, Kong MK, Ratbi I, Fejjal N, Fikri M, Elalaoui SC, Reigstad H, Bole-Feysot C, Nitschke P, Ragge N, Levy N, Tuncbilek G, Teo AS, Cunningham ML, Sefiani A, Kayserili H, Murphy JM, Chatdokmaiprai C, Hillmer AM, Wattanasirichaigoon D, Lyonnet S, Magdinier F, Javed A, Blewitt ME, Amiel J, Wollnik B, Reversade B. De novo mutations in SMCHD1 cause Bosma arhinia microphthalmia syndrome and abrogate nasal development. Nat Genet. 2017 Feb;49(2):249-255.

PubMed ID:

28067911

Bosma arhinia microphthalmia syndrome: Clinical report and review of the literature [3]

Brasseur B, Martin CM, Cayci Z, Burmeister L, Schimmenti LA. Bosma arhinia microphthalmia syndrome: Clinical report and review of the literature. Am J Med Genet A. 2016 May;170A(5):1302-7.

PubMed ID:

26842768