Long-term follow-up at King Faisal Specialist Hospital and Research Centre, Riyadh.
From published studies only
CA II Deficiency in Saudi Arabia
What do published studies and case reports tell us about Carbonic Anhydrase II deficiency in Saudi Arabia?
Figures from studies
Al-Rass General Hospital, Qassim, 2004–2008.
A Brain study of the Arabic mutation, with King Saud University researchers.
Only in the Saudi Aramco facilities cohort in the Eastern Province: 3 cases among 165,530 births.
These figures come from different groups and studies. Some people may appear in more than one report, so the numbers must not be added together to estimate the total number of affected people in the Kingdom.
How common is it in Saudi Arabia?
No verified, published national statistic currently covers Carbonic Anhydrase II deficiency across Saudi Arabia.
The available rate comes from one birth cohort at Saudi Aramco medical facilities in the Eastern Province, 1983–2008. That study recorded 3 carbonic anhydrase II deficiency cases among 165,530 live births, and its table lists an incidence of 2 per 100,000 live births in that cohort. It is not a national rate.
The Arabic mutation
CA2 c.232+1G>A is a splice-site change at the start of intron 2. In the literature it is called the Arabic mutation, not the Saudi mutation.
It was first described in Arabic kindreds and is one of the most often reported CA2 changes among Arab and Saudi patients. In the 2011 Brain study, all 23 affected people were homozygous for this splice-site change.
It is not the only change. Other CA2 variants have been reported. A 2016 Saudi report described a novel change, c.484delG, together with the Arabic mutation in the same person.
Published Saudi studies
1980
4 children from 3 Saudi families
Marble Brain Disease: Recessive Osteopetrosis, Renal Tubular Acidosis and Cerebral Calcification in Three Saudi Arabian Families.
King Faisal Specialist Hospital and Research Centre, Riyadh. An early description of the syndrome, before the enzyme defect was identified.
1986
4 new cases from 2 families
Carbonic anhydrase II deficiency syndrome: recessive osteopetrosis with renal tubular acidosis and cerebral calcification.
New Saudi cases, with enzyme deficiency measured in some family members.
1988
Two Saudi sisters
The Syndrome of Osteopetrosis, Renal Acidosis and Cerebral Calcification in Two Sisters.
A report of two sisters. The available abstract does not establish that they were from the Eastern Province, so the city is not stated here.
2002
Long-term follow-up of 35 Saudi children
Long-term follow up of carbonic anhydrase II deficiency syndrome.
King Faisal Specialist Hospital and Research Centre, Riyadh. Follow-up since 1979.
2003
Paralysis episodes
Paralysis Episodes in Carbonic Anhydrase II Deficiency.
One person with acute paralysis that was initially misdiagnosed. Indexed author affiliation: Riyadh Armed Forces Hospital.
2005
Two siblings in Asir
Marble brain disease in two Saudi Arabian siblings.
Asir Central Hospital. Two siblings whose growth improved after acidosis treatment, according to the report.
2010
18 new Saudi cases in Al-Rass
Carbonic anhydrase II deficiency syndrome: a report of 18 new Saudi Arabian cases.
Al-Rass General Hospital, Qassim, 2004–2008.
2010
Eastern Province IEM incidence study
Incidence and patterns of inborn errors of metabolism in the Eastern Province of Saudi Arabia, 1983–2008.
3 CA II cases among 165,530 births at Saudi Aramco facilities. The table lists 2 per 100,000 live births.
2011
23 affected people from 10 families
The neurology of carbonic anhydrase type II deficiency syndrome.
King Saud University. All 23 were homozygous for the Arabic mutation.
2015
One Saudi woman
Carbonic Anhydrase II Deficiency in a Saudi Woman.
A case report of the classic triad, homozygous for c.232+1G>A. The hospital is not established in the abstract available here.
2016
A novel change beside the Arabic mutation
Carbonic anhydrase II deficiency: report of a novel mutation.
King Saud University and King Faisal Specialist Hospital and Research Centre, Riyadh. One compound-heterozygous case.
2024
An unusual presentation of the Arabic mutation
Carbonic Anhydrase II Deficiency: Unusual Presentation of the Arabic Mutation. A Case Report.
King Fahad Medical City and King Saud Medical City, Riyadh. One child, with the Arabic mutation confirmed.
2024
10 genetically confirmed children at King Saud University Medical City
The correlation of intracranial parenchymal calcium score and the severity of neurological clinical presentation in carbonic anhydrase deficiency type 2.
King Saud University Medical City. Ten children diagnosed from 2015 to 2022. PubMed records publication on 12 December 2024, not 2025.
Saudi centres with published experience in diagnosis and follow-up
King Faisal Specialist Hospital & Research Centre — Riyadh
Medical Genetics / Genetic Metabolic Bone Diseases Clinic / Genomic Medicine. This is based on published series and long follow-up, not on an official statement that a clinic exists only for this condition.
King Fahad Medical City — Riyadh
Children's Specialized Hospital / Clinical and Metabolic Genetics. Named in a 2024 case report.
King Saud University Medical City — Riyadh
Has published research and follow-up of people with carbonic anhydrase II deficiency, including the 2024 series of 10 children.
Maternity and Children's Hospital — Buraidah, Qassim
Kidney unit. Follow-up of cases previously referred to medical laboratories to confirm the diagnosis.
Centres named in Saudi studies and case reports
Al-Rass General Hospital
Qassim. An 18-case series, 2004–2008.
Asir Central Hospital
Two siblings in a 2005 report.
King Saud Medical City
Riyadh. Named with King Fahad Medical City in the 2024 case report.
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Are you living with CA II deficiency in Saudi Arabia, or a family member with that diagnosis? The aim is to connect families, share experiences, and increase knowledge of the condition.
The information and figures are taken from published scientific literature. They are not an official national registry and do not represent the actual number of affected people in the Kingdom. This content is for awareness and is not a substitute for medical advice.