Do BRCA1 mutations affect the ability to breast feed? Significantly shorter length of breast feeding among BRCA1 mutation carriers compared with their unaffected relatives.

The difference in length of breast feeding between women with a BRCA 1 mutation and their unaffected relatives was investigated. Fifty women belonging to a family with a known BRCA1 mutation had themselves undergone testing and each had given birth to at least one child. Women with BRCA1 mutation breast-fed their first infant for a significantly shorter period (P = 0.048) and the second and third infants for a non-significantly shorter time than their unaffected relatives. Computing a mean breast-feeding time per child based on the first three infants and also taking birth year of the mother and smoking into account, having a BRCA1 mutation was associated with a significantly shorter time of breast-feeding (P = 0.034), and so was smoking (P = 0.001), but birth year of the woman did not significantly influence length of breast-feeding. Seventy-five per cent of the assessable women with a BRCA1 mutation stopped breast-feeding owing to little or no milk production compared with 36% of the non-carriers OR = 5.3 (CI 95% 1.1–22.1) and (P = 0.02). Our finding may reflect a disturbed differentiation of the breast tissue in women with BRCA1 mutations

Surging glacier landsystem of Tungnaárjökull, Iceland

A 1:30,000 scale map of the snout and proglacial landscape of the surging Icelandic glacier Tungnaarjokull, based upon aerial photography from 1995, immediately after a surge, allows an assessment of the spatial variability in landform-sediment imprints of catastrophic glacier advance across upland bedrock ridges. The ice-margin parallel alignment of the bedrock ridges locally strongly directs proglacial meltwater drainage and initiates strong compression in the ice during surging, resulting in the development of prominent ice-cored hummocky moraine composed of glacifluvial sediment. Diagnostic surge landforms elsewhere on the foreland include thrust block and push moraines, overridden ice-cored thrust block moraines, crevasse squeeze ridges, long flutings, hummocky moraine and ice-cored, pitted outwash