Overview
Congenital sucrase-isomaltase deficiency (CSID) with starch and lactose intolerance is a rare inherited digestive disorder. This entry in Orphanet is marked as 'OBSOLETE,' meaning it has been retired or reclassified, likely merged into the broader category of congenital sucrase-isomaltase deficiency (CSID). In this condition, the small intestine lacks enough of the enzymes sucrase and isomaltase, which are needed to break down certain sugars and starches from food. In this particular variant, there is also difficulty digesting lactose (the sugar found in milk and dairy products), making the intolerance broader than typical CSID. When a person with this condition eats foods containing sucrose (table sugar), starch, or lactose, the undigested sugars pass into the large intestine where bacteria ferment them. This leads to symptoms such as bloating, gas, abdominal cramps, and watery diarrhea. Symptoms usually begin in infancy when babies are first introduced to formula, breast milk (which contains lactose), fruit juices, or solid foods containing starch and sugar. If left unmanaged, the condition can lead to poor weight gain and growth problems in children. Treatment focuses on dietary changes — limiting or avoiding foods high in sucrose, starch, and lactose — and enzyme replacement therapy. The FDA-approved enzyme supplement sacrosidase (brand name Sucraid) can help break down sucrose, though it does not address starch or lactose digestion. Lactase supplements may also be used. With proper dietary management, most people with this condition can live healthy, normal lives.
Also known as:
Key symptoms:
Watery diarrhea after eating sugar, starch, or dairyBloating and abdominal distensionExcessive gas and flatulenceStomach cramps and abdominal painNausea and sometimes vomitingPoor weight gain in infants and childrenFailure to thriveIrritability in babies, especially after feedingDiaper rash from acidic stoolsDehydration from chronic diarrheaRumbling stomach sounds (borborygmi)
Autosomal recessive
Passed on when both parents carry the same gene change; often skips generations
Infantile
Begins in infancy, roughly 1 month to 2 years old
Treatments
No FDA-approved treatments are currently listed for OBSOLETE: Congenital sucrase-isomaltase deficiency with starch and lactose intolerance.
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Specialists
View all specialists →No specialists are currently listed for OBSOLETE: Congenital sucrase-isomaltase deficiency with starch and lactose intolerance.
Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Travel Grants
No travel grants are currently matched to OBSOLETE: Congenital sucrase-isomaltase deficiency with starch and lactose intolerance.
Community
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Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
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Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Questions for your doctor
Bring these to your next appointment
- Q1.How severe is my child's enzyme deficiency, and does it affect sucrose, starch, and lactose equally?,Should we start sacrosidase (Sucraid), and how do we use it properly?,What specific foods should we avoid, and are there safe alternatives?,Will my child's tolerance for these foods improve as they get older?,Should we see a dietitian to make sure my child is getting enough nutrition?,Are there genetic tests that should be done for other family members?,What should we do if my child accidentally eats a trigger food and has severe symptoms?
Common questions about OBSOLETE: Congenital sucrase-isomaltase deficiency with starch and lactose intolerance
What is OBSOLETE: Congenital sucrase-isomaltase deficiency with starch and lactose intolerance?
Congenital sucrase-isomaltase deficiency (CSID) with starch and lactose intolerance is a rare inherited digestive disorder. This entry in Orphanet is marked as 'OBSOLETE,' meaning it has been retired or reclassified, likely merged into the broader category of congenital sucrase-isomaltase deficiency (CSID). In this condition, the small intestine lacks enough of the enzymes sucrase and isomaltase, which are needed to break down certain sugars and starches from food. In this particular variant, there is also difficulty digesting lactose (the sugar found in milk and dairy products), making the in
How is OBSOLETE: Congenital sucrase-isomaltase deficiency with starch and lactose intolerance inherited?
OBSOLETE: Congenital sucrase-isomaltase deficiency with starch and lactose intolerance follows a autosomal recessive inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does OBSOLETE: Congenital sucrase-isomaltase deficiency with starch and lactose intolerance typically begin?
Typical onset of OBSOLETE: Congenital sucrase-isomaltase deficiency with starch and lactose intolerance is infantile. Age of onset can vary across affected individuals.