Pyloric stenosis is an example of a polygenic (multifactorial) disorder. The disease appears to have decreased in frequency (possibly due to better diagnosis) and therapy has improved. However, close relatives of the affected patient show a significant increase in risk.
General population (in England): 0.5% males (5 per 1,000); 0.1% females (1 per 1,000)
General observations:
(1) Male infants are more commonly affected than females (about 5 to 1).
(2) The presence in a female relative increases the risk more than that associated with a male relative.
(3) The presence of more than 1 affected first degree relatives in family increases the risk further (in range 9-13%, Passarge).
(4) These values apply to Caucasians. Some racial groups show a much lower rate.
|
Male Index Patient |
Carter (1961) |
Carter (1983) |
Harper (1998) |
|
brother |
3.2% |
6.5 (? 3.2)% |
3.8% |
|
sister |
3.0% |
2.8% |
2.7% |
|
son |
6.8% |
5.5% |
5.5% |
|
daughter |
1.2% |
2.4% |
2.4% |
|
second degree relative, male; nephew |
NA |
2.2% |
2.3% |
|
second degree relative, female; niece |
NA |
4.3 (0.5; see comment) |
0.4% |
|
first cousin, male |
NA |
NA |
0.9% |
|
first cousin, female |
NA |
NA |
0.2% |
|
Female Index Patient |
Carter (1961) |
Carter (1983) |
Harper (1998) |
|
brother |
13.2% |
10.8% |
9.2% |
|
sister |
2.5% |
3.8% |
3.8% |
|
son |
20.5% |
18.9% |
18.9% |
|
daughter |
11.1% |
7.0% |
7.0% |
|
second degree relative, male; nephew |
NA |
0.5 (4.3; see comment) |
4.7% |
|
second degree relative, female; niece |
NA |
1.7% |
NA |
|
first cousin, male |
NA |
NA |
0.7% |
|
first cousin, female |
NA |
NA |
0.3% |
where:
• The value for second degree relatives in Carter (1983) may be a typographical error. If the values for second degree relatives are switched, then values similar to those reported by Harper are seen.
Specialty: Genetics
ICD-10: ,
