Childhood blindness in qatar a high incidence of ho mocystinuria
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Childhood Blindness in Qatar A high incidence of ho mocystinuria. Richard Scawn, Dawn Sim, Charles Claoue Queens Hospital, Essex, UK. Richard Scawn has received travel sponsorship from Rayner The authors have no financial interest in the subject of this e-poster. Aim and Background.

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Childhood blindness in qatar a high incidence of ho mocystinuria

Childhood Blindness in QatarA high incidence of homocystinuria

Richard Scawn, Dawn Sim, Charles Claoue

Queens Hospital, Essex, UK

Richard Scawn has received travel sponsorship from Rayner

The authors have no financial interest in the subject of this e-poster

Aim and background
Aim and Background

  • The aim of our study was to determine the causes of childhood blindness in Qatar

  • One previous survey of blindness in adults and children of Qatar was carried out in 1977 1

  • The State of Qatar is an Arab emirate bordered by Saudi Arabia and the Persian Gulf.

  • With the discovery of oil in the 1940s came large changes in the socioeconomic wealth and population growth.

  • It is estimated that only about 30% of the country’s population (>1.4million), are citizens.

  • All Qataris receive free medical care

Al noor institute doha qatar
Al-Noor Institute, Doha, Qatar

  • Qatar’s only blind school

  • Opened in September of 1998

  • Provides a free education for citizens and residents

  • Students with blindness, low vision, and special needs


  • A visiting Ophthalmologist examined all children attending the Al-Noor Institute

  • The classification method used was that of the British Ophthalmological Surveillance Unit (BOSU) study3

    (1) entirely unavoidable/untreatable,

    (2) entirely preventable, or

    (3) potentially treatable

  • Outcomes of the consultation were grouped into 7 categories, including recommendations for

    (1) surgery, (2) further investigations, (3) low vision assessment,

    (4) refraction / contact lens / glasses, (5) mainstream school,

    (6) blind school(7) blind school with special needs


211 children examined


  • Homocystinuria was by far the most common single diagnosis.

  • In this group further intervention via cataract surgery or YAG laser capsulotomy required in 17% (n=7), refraction or low vision assessment was needed in 63% (n=26).

  • A small number of these children (n=4, 9.8%) had visual acuities that would enable them to attend mainstream school.


  • Homocystinuria incidence

    • Western Europe: 1 in 20,000-60,000 4

    • Norway: 1 in 6400

    • Qatar: 1 in 3125 5

  • Original Qatari tribes amount to about 200,000 people

  • Until the beginning of the 20th century the local Qatari tribes were genetically isolated, with a high level of intermarriage.

  • As in other Gulf States today it is still common for first- or second-degree cousins to marry6. 54% in Qatari population7

  • Consequent founder effects are responsible for the high prevalence and unusual burden of inherited disorders in Qatari population8


  • There has been a dramatic shift in the leading cause of blindness following economic development in Qatar

  • In our study genetic diseases account for almost 80%

  • Improved education, genetic counseling and screening programs8 may reduce the future incidence of genetically determined causes of blindness in Qatar


  • Hosni FA. Survey of major blinding conditions in Qatar. Ophthalmologica. 1977; 175(4):215-21.

  • Vision for Children. A global overview of blindness, childhood and VISION2020: the right to sight. World Health Organization (WHO) and the International Agency for the Prevention of Blindness (IAPB). Accessed April 2009.

  • Durnian JM, Cheeseman R, Kumar A, Raja V, Newman W, Chandna A. Eye. Childhood sight impairment: a 10-year picture. 2009 Feb 27.

  • Mudd SH, Levy HL, Kraus JP. Disorders of transsulfuration. In: Scriver CR, Beaudet AL, Sly WS, Valle D, editors. The Metabolic and Molecular Bases of Inherited Disease. New York: McGraw-Hill. 2001 p 2007-56.

  • El-Said MF, Badii R, Bessisso MS, Shahbek N, El-Ali MG, El-Marikhie M, El-Zyoid M, Salem MS, Bener A, Hoffmann GF, Zschocke J. A common mutation in the CBS gene explains a high incidence of homocystinuria in the Qatari population. Hum Mutat. 2006; 27(7):719.

  • Al-Gazali LI, Bener A, Abdulrazzaq YM, Micallef R, al-Khayat AI, Gaber T. Consanguineous marriages in the United Arab Emirates. J Biosoc Sci 1997; 29:491-7.

  • Bener A, Alali KA.Consanguineous marriage in a newly developed country: the Qatari population. J Biosoc Sci. 2006; 38(2):239-46.

  • Lindner M, Abdoh G, Fang-Hoffmann J, Shabeck N, Al-Sayrafi M, Al-Janahi M, Ho S, Abdelrahman MO, Ben-Omran T, Bener A, Schulze A, Al-Rifai H, Al-Thani G, Hoffmann GF. Implementation of extended neonatal screening and a metabolic unit in the State of Qatar: developing and optimizing strategies in cooperation with the Neonatal Screening Center in Heidelberg. J Inherit Metab Dis. 2007; 30(4):522-9.