Bosch–Boonstra–Schaaf optic atrophy syndrome explained

Bosch–Boonstra–Schaaf optic atrophy syndrome
Synonyms:	BBSOAS^[1]
Causes:	mutations in the NR2F1 gene

Bosch–Boonstra–Schaaf optic atrophy syndrome is a rare autosomally inherited condition characterised by developmental delay, intellectual disability and decreased visual acuity.^{[2] [3] [4]}

Presentation

All patients described have suffered from developmental delay, intellectual disability (intelligence quotient range 48–74) and decreased visual acuity. Ocular abnormalities include small discs, pale discs, disc excavation, strabismus and latent nystagmus.

Other features of this condition are somewhat variable and include:

• Facial indicators
  • Protruding ears
  • Helical anomalies
  • Small nasal ridge
  • High nasal bridge
  • Upturned nose
  • Epicanthal folds
  • Upslanting palpebral fissures
• Skeletal indicators
  • Tapering fingers
  • Hypotonia

Genetics

This condition is caused by mutations in the NR2F1 gene. This gene is located on the long arm of chromosome 5 (5q15) and encodes a protein that acts as a nuclear receptor and transcriptional regulator. The syndrome is inherited in an autosomal dominant fashion.

Management

There is no curative treatment known at present for his condition. Management is supportive.

Epidemiology

This condition is considered to be rare with fewer than 50 cases described in the modern literature.

History

This condition was first described in 2014.^[2]

Notes and References

1. Web site: OMIM Entry – # 615722 – Bosch-Boonstra-Schaaf Optic Atrophy Syndrome; BBSOAS . omim.org . 19 January 2020.
2. Bosch . Daniëlle G.M. . Boonstra . F. Nienke . Gonzaga-Jauregui . Claudia . Xu . Mafei . de Ligt . Joep . Jhangiani . Shalini . Wiszniewski . Wojciech . Muzny . Donna M. . Yntema . Helger G. . Pfundt . Rolph . Vissers . Lisenka E.L.M. . Spruijt . Liesbeth . Blokland . Ellen A.W. . Chen . Chun-An . Lewis . Richard A. . Tsai . Sophia Y. . Gibbs . Richard A. . Tsai . Ming-Jer . Lupski . James R. . Zoghbi . Huda Y. . Cremers . Frans P.M. . de Vries . Bert B.A. . Schaaf . Christian P. . NR2F1 Mutations Cause Optic Atrophy with Intellectual Disability . The American Journal of Human Genetics . Elsevier BV . 94 . 2 . 2014 . 0002-9297 . 10.1016/j.ajhg.2014.01.002 . 303–309. 3928641 .
3. Chen . Chun-An . Bosch . Daniëlle G.M. . Cho . Megan T. . Rosenfeld . Jill A. . Shinawi . Marwan . Lewis . Richard Alan . Mann . John . Jayakar . Parul . Payne . Katelyn . Walsh . Laurence . Moss . Timothy . Schreiber . Allison . Schoonveld . Cheri . Monaghan . Kristin G. . Elmslie . Frances . Douglas . Ganka . Boonstra . F. Nienke . Millan . Francisca . Cremers . Frans P.M. . McKnight . Dianalee . Richard . Gabriele . Juusola . Jane . Kendall . Fran . Ramsey . Keri . Anyane-Yeboa . Kwame . Malkin . Elfrida . Chung . Wendy K. . Niyazov . Dmitriy . Pascual . Juan M. . Walkiewicz . Magdalena . Veluchamy . Vivekanand . Li . Chumei . Hisama . Fuki M. . de Vries . Bert B.A. . Schaaf . Christian . The expanding clinical phenotype of Bosch-Boonstra-Schaaf optic atrophy syndrome: 20 new cases and possible genotype–phenotype correlations . Genetics in Medicine . Elsevier BV . 18 . 11 . 2016 . 1098-3600 . 10.1038/gim.2016.18 . 1143–1150.
4. Chen . Chun-An . Wang . Wei . Pedersen . Steen E . Raman . Ayush . Seymour . Michelle L . Ruiz . Fernanda R . Xia . Anping . van der Heijden . Meike E . Wang . Li . Yin . Jiani . Lopez . Joanna . Rech . Megan E . Lewis . Richard A . Wu . Samuel M . Liu . Zhandong . Pereira . Fred A . Pautler . Robia G . Zoghbi . Huda Y . Schaaf . Christian P . Nr2f1 heterozygous knockout mice recapitulate neurological phenotypes of Bosch-Boonstra-Schaaf optic atrophy syndrome and show impaired hippocampal synaptic plasticity . Human Molecular Genetics . 29 . 5 . 2020-03-27 . 0964-6906 . 31600777 . 7104670 . 10.1093/hmg/ddz233 . 705–715.