FRAS1 gene


Gene (OMIM No.)
Function of gene/protein
  • Protein: fraser extracellular matrix complex subunit 1
  • Part of the FRAS/FREM complex, which is vital during embryogenesis
  • The complex is located in cells basement membranes, and plays a role in anchoring cell layers in tissues
Clinical phenotype
(OMIM phenotype no.)
  • Autosomal recessive
Ocular features
Systemic featuresMain features:
  • Cutaneous syndactyly of both upper and lower limbs
  • Laryngeal malformation (stenosis/atresia)
  • Genital anomalies (micropenis, hypospadias, cryptorchidism, clitoral enlargement, vaginal atresia, bicornuate uterus)
Additional features:
  • Microcephaly, meningomyelocele, encephalocele
  • Orofacial clefting (lip, palate, uvula)
  • Nasal anomalies (hypoplastic, notched nares; broad, low nasal bridge; midline nasal cleavage)
  • Middle and external ear malformations
  • Unusual hairline with hair growth on temples extending to lateral eyebrow
  • Displacement of the umbilicus and nipples
  • Renal agenesis/hypoplasia
  • Diastasis of pubic symphysis
  • Intellectual disability
Key investigations
  • B-scan USS to measure axial length to document microphthalmia
  • Electrophysiology
  • MRI brain and orbit
  • Systemic assessment with a paediatrician and other relevant specialists
Molecular diagnosisNext generation sequencing
  • Targeted gene panels (MAC)
  • Whole genome sequencing
  • Multidisciplinary approach
Therapies under research
  • None at present
Further information

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  1.  Gupta SP, Saxena RC. CRYPTOPHTHALMOS. Br J Ophthalmol. 1962;46(10):629‐632
  2.  Petrou P, Pavlakis E, Dalezios Y, Galanopoulos VK, Chalepakis G. Basement membrane distortions impair lung lobation and capillary organization in the mouse model for fraser syndrome. J Biol Chem. 2005;280(11):10350‐10356
  3.  van Haelst MM, Maiburg M, Baujat G, et al. Molecular study of 33 families with Fraser syndrome new data and mutation review. Am J Med Genet A. 2008;146A(17):2252‐2257
  4.  Vrontou S, Petrou P, Meyer BI, et al. Fras1 deficiency results in cryptophthalmos, renal agenesis and blebbed phenotype in mice. Nat Genet. 2003;34(2):209‐214
  5.  Saleh GM, Hussain B, Verity DH, Collin JR. A surgical strategy for the correction of Fraser syndrome cryptophthalmos. Ophthalmology. 2009;116(9):1707‐1712
  6.  Slavotinek AM, Tifft CJ. Fraser syndrome and cryptophthalmos: review of the diagnostic criteria and evidence for phenotypic modules in complex malformation syndromes. J Med Genet. 2002;39(9):623‐633. doi:10.1136/jmg.39.9.623

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Updated on November 30, 2020
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