Lactose intolerance classification: Difference between revisions
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* Convergent evolution of lactase persistence is seen in some populations in Africa that domesticate cows and consume milks product into adulthood <ref name="pmid17159977">{{cite journal |vauthors=Tishkoff SA, Reed FA, Ranciaro A, Voight BF, Babbitt CC, Silverman JS, Powell K, Mortensen HM, Hirbo JB, Osman M, Ibrahim M, Omar SA, Lema G, Nyambo TB, Ghori J, Bumpstead S, Pritchard JK, Wray GA, Deloukas P |title=Convergent adaptation of human lactase persistence in Africa and Europe |journal=Nat. Genet. |volume=39 |issue=1 |pages=31–40 |year=2007 |pmid=17159977 |pmc=2672153 |doi=10.1038/ng1946 |url=}}</ref> | * Convergent evolution of lactase persistence is seen in some populations in Africa that domesticate cows and consume milks product into adulthood <ref name="pmid17159977">{{cite journal |vauthors=Tishkoff SA, Reed FA, Ranciaro A, Voight BF, Babbitt CC, Silverman JS, Powell K, Mortensen HM, Hirbo JB, Osman M, Ibrahim M, Omar SA, Lema G, Nyambo TB, Ghori J, Bumpstead S, Pritchard JK, Wray GA, Deloukas P |title=Convergent adaptation of human lactase persistence in Africa and Europe |journal=Nat. Genet. |volume=39 |issue=1 |pages=31–40 |year=2007 |pmid=17159977 |pmc=2672153 |doi=10.1038/ng1946 |url=}}</ref> | ||
* Persistence of intestinal lactase until adulthood is inherited as autosomal-dominant characteristic<ref name="pmid3140651">{{cite journal |vauthors=Scrimshaw NS, Murray EB |title=The acceptability of milk and milk products in populations with a high prevalence of lactose intolerance |journal=Am. J. Clin. Nutr. |volume=48 |issue=4 Suppl |pages=1079–159 |year=1988 |pmid=3140651 |doi= |url=}}</ref> | * Persistence of intestinal lactase until adulthood is inherited as autosomal-dominant characteristic<ref name="pmid3140651">{{cite journal |vauthors=Scrimshaw NS, Murray EB |title=The acceptability of milk and milk products in populations with a high prevalence of lactose intolerance |journal=Am. J. Clin. Nutr. |volume=48 |issue=4 Suppl |pages=1079–159 |year=1988 |pmid=3140651 |doi= |url=}}</ref> | ||
* In particular, presence of the T allele of the SNP located at -13.9 kb upstream of the lactase gene has been strongly correlated with lactase persistence | |||
* Multiple single nucleotide polymorphisms (SNPs) in the DNA sequence of the coding region and the regulatory region of the lactase gene on 2q21 have been identified. | * Multiple single nucleotide polymorphisms (SNPs) in the DNA sequence of the coding region and the regulatory region of the lactase gene on 2q21 have been identified. | ||
* Several in vitro studies have suggested that this allele regulates levels of lactase mRNA and thus lactase persistence | |||
* A CC genotype at -13910 C/T polymorphism is associated with acquired primary lactase deficiency (adult-type hypolactasia), whereas TC and TT genotypes are linked with lactase persistence | |||
OR | OR | ||
*[Disease name] may be classified into [large number > 6] subtypes based on: | *[Disease name] may be classified into [large number > 6] subtypes based on: | ||
Revision as of 14:44, 28 November 2017
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Lactose intolerance classification On the Web |
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Risk calculators and risk factors for Lactose intolerance classification |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mahda Alihashemi M.D. [2]
Overview
There is no established system for the classification of [disease name].
OR
[Disease name] may be classified according to [classification method] into [number] subtypes/groups: [group1], [group2], [group3], and [group4].
OR
[Disease name] may be classified into [large number > 6] subtypes based on [classification method 1], [classification method 2], and [classification method 3]. [Disease name] may be classified into several subtypes based on [classification method 1], [classification method 2], and [classification method 3].
OR
Based on the duration of symptoms, [disease name] may be classified as either acute or chronic.
OR
If the staging system involves specific and characteristic findings and features: According to the [staging system + reference], there are [number] stages of [malignancy name] based on the [finding1], [finding2], and [finding3]. Each stage is assigned a [letter/number1] and a [letter/number2] that designate the [feature1] and [feature2].
OR
The staging of [malignancy name] is based on the [staging system].
OR
There is no established system for the staging of [malignancy name].
Classification
- There is no established system for the classification of [disease name].
OR
- Lactose intolerance may be classified according to its causes into 2 groups:
- Primary lactose malabsorption
- Secondary lactose malabsorption
- Primary lactose malabsorption may be classified into 3 subtypes include:
- Acquired primary lactase deficiency
- Congenital lactase deficiency
- Developmental lactase deficiency
Acquired primary lactase deficiency (adult-type hypolactasia, lactase nonpersistence)
- The most common cause of primary lactase malabsorbtion
- Autosomal recessive condition[1]
- Intestinal lactase levels is deceresed at preschool age in many populations especially in Asia and Africa
- Elevated lactase activity is maintained in Caucasians such as northern European
- Convergent evolution of lactase persistence is seen in some populations in Africa that domesticate cows and consume milks product into adulthood [2]
- Persistence of intestinal lactase until adulthood is inherited as autosomal-dominant characteristic[3]
- In particular, presence of the T allele of the SNP located at -13.9 kb upstream of the lactase gene has been strongly correlated with lactase persistence
- Multiple single nucleotide polymorphisms (SNPs) in the DNA sequence of the coding region and the regulatory region of the lactase gene on 2q21 have been identified.
- Several in vitro studies have suggested that this allele regulates levels of lactase mRNA and thus lactase persistence
- A CC genotype at -13910 C/T polymorphism is associated with acquired primary lactase deficiency (adult-type hypolactasia), whereas TC and TT genotypes are linked with lactase persistence
OR
- [Disease name] may be classified into [large number > 6] subtypes based on:
- [Classification method 1]
- [Classification method 2]
- [Classification method 3]
- [Disease name] may be classified into several subtypes based on:
- [Classification method 1]
- [Classification method 2]
- [Classification method 3]
OR
- Based on the duration of symptoms, [disease name] may be classified as either acute or chronic.
OR
- If the staging system involves specific and characteristic findings and features:
- According to the [staging system + reference], there are [number] stages of [malignancy name] based on the [finding1], [finding2], and [finding3]. Each stage is assigned a [letter/number1] and a [letter/number2] that designate the [feature1] and [feature2].
OR
- The staging of [malignancy name] is based on the [staging system].
OR
- There is no established system for the staging of [malignancy name].
References
- ↑ Enattah NS, Sahi T, Savilahti E, Terwilliger JD, Peltonen L, Järvelä I (2002). "Identification of a variant associated with adult-type hypolactasia". Nat. Genet. 30 (2): 233–7. doi:10.1038/ng826. PMID 11788828.
- ↑ Tishkoff SA, Reed FA, Ranciaro A, Voight BF, Babbitt CC, Silverman JS, Powell K, Mortensen HM, Hirbo JB, Osman M, Ibrahim M, Omar SA, Lema G, Nyambo TB, Ghori J, Bumpstead S, Pritchard JK, Wray GA, Deloukas P (2007). "Convergent adaptation of human lactase persistence in Africa and Europe". Nat. Genet. 39 (1): 31–40. doi:10.1038/ng1946. PMC 2672153. PMID 17159977.
- ↑ Scrimshaw NS, Murray EB (1988). "The acceptability of milk and milk products in populations with a high prevalence of lactose intolerance". Am. J. Clin. Nutr. 48 (4 Suppl): 1079–159. PMID 3140651.
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Lactose Intolerance Microchapters |
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Diagnosis |
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Treatment |
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Case Studies |
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Lactose intolerance classification On the Web |
|
American Roentgen Ray Society Images of Lactose intolerance classification |
|
Risk calculators and risk factors for Lactose intolerance classification |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [3]
Overview
There are three major types of lactose intolerance.[1] They are primary lactose intolerance, secondary lactose intolerance and congenital lactase deficiency.
Classification
There are three major types of lactose intolerance:[1]
- Primary lactose intolerance: Environmentally induced by weaning in non dairy consuming societies. In most Asian and African cultures, mother's milk is the only commonly available milk and so milk consumption beyond infancy is not commonplace, therefore children become weaned, which is the same weaning process for all mammals (domesticated and wild). However societies such as the japanese where milk consumption has been on the increase, demonstrate that notwithstanding the genetic predisposition to lactose intolerance, they now present lower prevalence of lactose intolerance.[2] For any given individual the degree of weaning is probably genetically influenced.
- Secondary lactose intolerance: Environmentally induced, resulting from certain gastrointestinal diseases, including exposure to intestinal parasites such as giardia.[3][4] In such cases the production of lactase may be permanently disrupted.[5]
- Congenital lactase deficiency present at birth and diagnosed in early infancy.
References
- ↑ 1.0 1.1 B. Heyman. Lactose Intolerance in Infants, Children, and Adolescents. PEDIATRICS Vol. 118 No. 3 September 2006, pp. 1279-1286 (doi:10.1542/peds.2006-1721)
- ↑ Studies on the etiology of milk intolerance in Japanese adults, Yoshida Y, Sasaki G, Goto S, Yanagiya S, Takashina K, Gastroenterol Jpn.;10(1):29–34, 1975
- ↑ "Intestinal Protozoa" Mark Wiser 2000
- ↑ "Giardiasis" Andre Pennardt February 22, 2006
- ↑ "Lactose Intolerance - May 1, 2002 - American Family Physician". Retrieved 2013-04-01.