*104650	Links
AMYLASE, PANCREATIC, A; AMY2A

Gene map locus 1p21

TEXT

Polymorphism was determined by agar gel electrophoresis. Data on gene frequencies of allelic variants were tabulated by Roychoudhury and Nei (1988).

Kamaryt et al. (1971) assigned the locus to chromosome 1 by study of linkage with the 'uncoiler' chromosomal variant (1qh+) used by Donahue et al. (1968) in assigning the Duffy blood group locus (110700) to chromosome 1. Hill et al. (1972) demonstrated probable linkage between the AMY2 locus and the Duffy blood group locus. In the mouse, Hjorth et al. (1980) concluded that at least 4 structural gene loci code for pancreatic amylase, whereas only a single gene, different from any of the pancreatic genes, codes for salivary amylase. These genes are on mouse chromosome 3. Young et al. (1981) showed that in the mouse two different tissue-specific mRNAs are coded by a single gene. Using a human genomic DNA segment that hybridizes with rat pancreatic amylase cDNA to study human-mouse somatic cell hybrids, Tricoli and Shows (1984) assigned the amylase gene(s) to region 1p22-p21. The human cell studied in the hybrid had a translocation involving chromosome 1. RFLPs at the amylase loci were described. Groot et al. (1988) suggested that there are 2 pancreatic amylase genes in the human genome, designated AMY2A and AMY2B (104660). Pronk et al. (1982) presented evidence they interpreted as indicating duplication of the salivary amylase locus also. In a full exposition of the structure of the part of the genome containing the alpha-amylase multigene family, Groot et al. (1989) described 2 haplotypes consisting of different numbers of salivary amylase genes: the short haplotype contains 2 pancreatic genes, termed by them AMY2A and AMY2B, and 1 salivary amylase gene, termed by them AMY1C, arranged in the order 2B-2A-1C and encompassing a total length of approximately 100 kb. The long haplotype spans about 300 kb and contains 6 additional genes arranged in 2 repeats, each of which consists of 2 salivary amylase genes, designated AMY1A (104700) and AMY1B, and a pseudogene lacking the first 3 exons (AMYP1). The order of the amylase genes within the repeat is 1A-1B-P1. All genes are in a head-to-tail orientation except AMY1B, which has a reverse orientation with respect to the other genes. A general designation 2B-2A-(1A-1B-P)n-1C can describe these haplotypes, n being 0 and 2 for the short and long haplotypes, respectively. Groot et al. (1989) presented evidence for the existence of additional haplotypes. Groot et al. (1990) proposed that the alpha-amylase multigene family evolved through unequal, homologous, inter- and intrachromosomal crossovers. Groot et al. (1991) reported observations on polymorphic DNA patterns and interpreted them in light of this hypothesis.

Brock et al. (1988), Jorgensen et al. (1984), and Sjolund et al. (1991) reported familial selective deficiency of pancreatic amylase. The patients of Sjolund et al. (1991) were unrelated women aged 49 and 38 years. In the second woman reduced levels of serum amylase were found in a sister and her only son. The sister had a daughter with 'slightly reduced pancreatic amylase activity in serum.' In young children, physiologically low levels of pancreatic amylase activity are observed. The adult level of activity in the duodenal juice is reached at the age of 18 months and in serum at about age 7 years, although delayed maturation has been described.

Large-scale copy number variations (LCVs) involve gains or losses of several kilobases to hundreds of kilobases of genomic DNA among phenotypically normal individuals. To investigate LCVs in the human genome, Iafrate et al. (2004) applied array-based comparative genomic hybridization (array CGH) to the genomes of 55 unrelated individuals. The most common LCV (identified in 49.1% of the individuals studied) encompassed the AMY1A and AMY2A locus at 1p13.3 (Groot et al., 1991).

SEE ALSO

Carfagna et al. (1976); Merritt et al. (1973); Merritt et al. (1973); Merritt et al. (1972); Rosenblum and Merritt (1978); Spence et al. (1977)

REFERENCES

1. Brock, A.; Mortensen, P. B.; Mortensen, B. B.; Roge, H. R. :

Familial occurrence of diminished pancreatic amylase in serum--a 'silent' Amy-2 allelic variant? Clin. Chem. 34: 1516-1517, 1988.
PubMed ID : 3260546

2. Carfagna, M.; Gaudio, L.; Patricolo, M. R.; Spadacenta, F. :

Pancreatic amylase polymorphism: another example of a distinctive gene frequency among Sardinians. Hum. Hered. 26: 59-65, 1976.
PubMed ID : 955637

3. Donahue, R. P.; Bias, W. B.; Renwick, J. H.; McKusick, V. A. :

Probable assignment of the Duffy blood group locus to chromosome 1 in man. Proc. Nat. Acad. Sci. 61: 949-955, 1968.
PubMed ID : 5246559

4. Groot, P. C.; Bleeker, M. J.; Pronk, J. C.; Arwert, F.; Mager, W. H.; Planta, R. J.; Eriksson, A. W.; Frants, R. R. :

Human pancreatic amylase is encoded by two different genes. Nucleic Acids Res. 16: 4724 only, 1988.
PubMed ID : 3260028

5. Groot, P. C.; Bleeker, M. J.; Pronk, J. C.; Arwert, F.; Mager, W. H.; Planta, R. J.; Eriksson, A. W.; Frants, R. R. :

The human alpha-amylase multigene family consists of haplotypes with variable numbers of genes. Genomics 5: 29-42, 1989.
PubMed ID : 2788608

6. Groot, P. C.; Mager, W. H.; Frants, R. R. :

Interpretation of polymorphic DNA patterns in the human alpha-amylase multigene family. Genomics 10: 779-785, 1991.
PubMed ID : 1679752

7. Groot, P. C.; Mager, W. H.; Henriquez, N. V.; Pronk, J. C.; Arwert, F.; Planta, R. J.; Eriksson, A. W.; Frants, R. R. :

Evolution of the human alpha-amylase multigene family through unequal, homologous, and inter- and intrachromosomal crossovers. Genomics 8: 97-105, 1990.
PubMed ID : 2081604

8. Hill, C. J.; Rowe, S. I.; Lovrien, E. W. :

Probable genetic linkage between human serum amylase (AMY-2) and Duffy blood groups. Nature 235: 162-163, 1972.
PubMed ID : 4551225

9. Hjorth, J. P.; Lusis, A. J.; Nielsen, J. T. :

Multiple structural genes for mouse amylase. Biochem. Genet. 18: 281-302, 1980.
PubMed ID : 6160849

10. Iafrate, A. J.; Feuk, L.; Rivera, M. N.; Listewnik, M. L.; Donahoe, P. K.; Qi, Y.; Scherer, S. W.; Lee, C. :

Detection of large-scale variation in the human genome. Nature Genet. 36: 949-951, 2004.
PubMed ID : 15286789

11. Jorgensen, H. R.; Kristensen, B.; Mortensen, P. B. :

Familial incidence of reduced activity of pancreas correlated with amylase-isoenzyme in the serum. Ugeskr. Laeger 146: 657-659, 1984.
PubMed ID : 6200983

12. Kamaryt, J.; Adamek, R.; Vrba, M. :

Possible linkage between uncoiler chromosome Un 1 and amylase polymorphism Amy 2 loci. Humangenetik 11: 213-220, 1971.
PubMed ID : 5101659

13. Merritt, A. D.; Lovrien, E. W.; Rivas, M. L.; Conneally, P. M. :

Human amylase loci: genetic linkage with the Duffy blood group locus and assignment to linkage group I. Am. J. Hum. Genet. 25: 523-538, 1973.
PubMed ID : 4741847

14. Merritt, A. D.; Rivas, M. L.; Bixler, D.; Newell, R. :

Salivary and pancreatic amylase: electrophoretic characterizations and genetic studies. Am. J. Hum. Genet. 25: 510-522, 1973.
PubMed ID : 4741846

15. Merritt, A. D.; Rivas, M. L.; Ward, J. C. :

Evidence for close linkage of human amylase loci. Nature N.B. 239: 243-244, 1972.

16. Pronk, J. C.; Frants, R. R.; Jansen, W.; Eriksson, A. W.; Tonino, G. J. M. :

Evidence for duplication of the human salivary amylase gene. Hum. Genet. 60: 32-35, 1982.
PubMed ID : 6176528

17. Rosenblum, B. B.; Merritt, A. D. :

Human pancreatic alpha-amylase: phenotypic codominance and new electrophoretic variants. Am. J. Hum. Genet. 30: 434-441, 1978.
PubMed ID : 309725

18. Roychoudhury, A. K.; Nei, M. :

Human Polymorphic Genes: World Distribution. New York: Oxford Univ. Press (pub.) 1988.

19. Sjolund, K.; Haggmark, A.; Ihse, I.; Skude, G.; Karnstrom, U.; Wikander, M. :

Selective deficiency of pancreatic amylase. Gut 32: 546-548, 1991.
PubMed ID : 1710200

20. Spence, M. A.; Sparkes, R. S.; Heckenlively, J. R.; Pearlman, J. T.; Zedalis, D.; Sparkes, M.; Crist, M.; Tideman, S. :

Probable genetic linkage between autosomal dominant retinitis pigmentosa (RP) and amylase (AMY-2): evidence of an RP locus on chromosome 1. Am. J. Hum. Genet. 29: 397-404, 1977.
PubMed ID : 879170

21. Tricoli, J. V.; Shows, T. B. :

Regional assignment of human amylase (AMY) to p22-p21 of chromosome 1. Somat. Cell Molec. Genet. 10: 205-210, 1984.
PubMed ID : 6608795

22. Young, R. A.; Hagenbuchle, O.; Schibler, U. :

A single mouse alpha-amylase gene specifies two different tissue-specific mRNAs. Cell 23: 451-458, 1981.
PubMed ID : 6162570

CONTRIBUTORS

Victor A. McKusick - updated : 9/30/2004

CREATION DATE

Victor A. McKusick : 6/4/1986

EDIT HISTORY

alopez : 9/30/2004
alopez : 9/30/2004
terry : 4/30/1999
pfoster : 5/12/1994
mimadm : 4/26/1994
warfield : 3/23/1994
supermim : 3/16/1992
carol : 2/18/1992
carol : 7/24/1991

Copyright © 1966-2007 Johns Hopkins University