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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®

Horizontal gaze palsy with progressive scoliosis

(often shortened to HGPPS)
Reviewed March 2009

What is HGPPS?

Horizontal gaze palsy with progressive scoliosis (HGPPS) is a disorder that affects vision and also causes an abnormal curvature of the spine (scoliosis). People with this condition are unable to move their eyes side-to-side (horizontally). As a result, affected individuals must turn their head instead of moving their eyes to track moving objects. Up-and-down (vertical) eye movements are typically normal.

In people with HGPPS, an abnormal side-to-side curvature of the spine develops in infancy or childhood. It tends to be moderate to severe and worsens over time. Because the abnormal spine position can be painful and interfere with movement, it is often treated with surgery early in life.

How common is HGPPS?

HGPPS has been reported in several dozen families worldwide.

What genes are related to HGPPS?

HGPPS is caused by mutations in the ROBO3 gene. This gene provides instructions for making a protein that is important for the normal development of certain nerve pathways in the brain. These include motor nerve pathways, which transmit information about voluntary muscle movement, and sensory nerve pathways, which transmit information about sensory input (such as touch, pain, and temperature). For the brain and the body to communicate effectively, these nerve pathways must cross from one side of the body to the other in the brainstem, a region that connects the upper parts of the brain with the spinal cord.

The ROBO3 protein plays a critical role in ensuring that motor and sensory nerve pathways cross over in the brainstem. In people with HGPPS, these pathways do not cross over, but stay on the same side of the body. Researchers believe that this miswiring in the brainstem is the underlying cause of the eye movement abnormalities associated with the disorder. The cause of progressive scoliosis in HGPPS is unclear. Researchers are working to determine why the effects of ROBO3 mutations appear to be limited to horizontal eye movement and scoliosis.

Related Gene(s)

Changes in this gene are associated with horizontal gaze palsy with progressive scoliosis.

  • ROBO3

How do people inherit HGPPS?

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Where can I find information about diagnosis or management of HGPPS?

These resources address the diagnosis or management of HGPPS and may include treatment providers.

  • Genetic Testing Registry: Gaze palsy, familial horizontal, with progressive scoliosis (

You might also find information on the diagnosis or management of HGPPS in Educational resources and Patient support.

General information about the diagnosis ( and management ( of genetic conditions is available in the Handbook. Read more about genetic testing (, particularly the difference between clinical tests and research tests (

To locate a healthcare provider, see How can I find a genetics professional in my area? ( in the Handbook.

Where can I find additional information about HGPPS?

You may find the following resources about HGPPS helpful. These materials are written for the general public.

You may also be interested in these resources, which are designed for healthcare professionals and researchers.

What other names do people use for HGPPS?

  • familial horizontal gaze palsy with progressive scoliosis
  • familial idiopathic scoliosis associated with congenital encephalopathy
  • familial infantile scoliosis associated with bilateral paralysis of conjugate gaze
  • gaze palsy, familial horizontal, with progressive scoliosis
  • ophthalmoplegia, progressive external, and scoliosis

For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines ( and How are genetic conditions and genes named? ( in the Handbook.

What if I still have specific questions about HGPPS?

Ask the Genetic and Rare Diseases Information Center (

What glossary definitions help with understanding HGPPS?

autosomal ; autosomal recessive ; bilateral ; brainstem ; cell ; congenital ; encephalopathy ; familial ; gene ; idiopathic ; inherited ; motor ; ophthalmoplegia ; palsy ; protein ; recessive ; scoliosis ; sensory nerve ; surgery ; voluntary muscle

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.


  • Abu-Amero KK, al Dhalaan H, al Zayed Z, Hellani A, Bosley TM. Five new consanguineous families with horizontal gaze palsy and progressive scoliosis and novel ROBO3 mutations. J Neurol Sci. 2009 Jan 15;276(1-2):22-6. doi: 10.1016/j.jns.2008.08.026. Epub 2008 Oct 1. (
  • Bosley TM, Salih MA, Jen JC, Lin DD, Oystreck D, Abu-Amero KK, MacDonald DB, al Zayed Z, al Dhalaan H, Kansu T, Stigsby B, Baloh RW. Neurologic features of horizontal gaze palsy and progressive scoliosis with mutations in ROBO3. Neurology. 2005 Apr 12;64(7):1196-203. (
  • Chan WM, Traboulsi EI, Arthur B, Friedman N, Andrews C, Engle EC. Horizontal gaze palsy with progressive scoliosis can result from compound heterozygous mutations in ROBO3. J Med Genet. 2006 Mar;43(3):e11. (
  • Engle EC. Oculomotility disorders arising from disruptions in brainstem motor neuron development. Arch Neurol. 2007 May;64(5):633-7. Review. (
  • Jen J, Coulin CJ, Bosley TM, Salih MA, Sabatti C, Nelson SF, Baloh RW. Familial horizontal gaze palsy with progressive scoliosis maps to chromosome 11q23-25. Neurology. 2002 Aug 13;59(3):432-5. (
  • Jen JC, Chan WM, Bosley TM, Wan J, Carr JR, Rüb U, Shattuck D, Salamon G, Kudo LC, Ou J, Lin DD, Salih MA, Kansu T, Al Dhalaan H, Al Zayed Z, MacDonald DB, Stigsby B, Plaitakis A, Dretakis EK, Gottlob I, Pieh C, Traboulsi EI, Wang Q, Wang L, Andrews C, Yamada K, Demer JL, Karim S, Alger JR, Geschwind DH, Deller T, Sicotte NL, Nelson SF, Baloh RW, Engle EC. Mutations in a human ROBO gene disrupt hindbrain axon pathway crossing and morphogenesis. Science. 2004 Jun 4;304(5676):1509-13. Epub 2004 Apr 22. (
  • Jen JC. Effects of failure of development of crossing brainstem pathways on ocular motor control. Prog Brain Res. 2008;171:137-41. doi: 10.1016/S0079-6123(08)00618-3. (
  • Sicotte NL, Salamon G, Shattuck DW, Hageman N, Rüb U, Salamon N, Drain AE, Demer JL, Engle EC, Alger JR, Baloh RW, Deller T, Jen JC. Diffusion tensor MRI shows abnormal brainstem crossing fibers associated with ROBO3 mutations. Neurology. 2006 Aug 8;67(3):519-21. (


The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? ( in the Handbook.

Reviewed: March 2009
Published: February 8, 2016