At first I thought it was a mistake on my ggg-grandmother's 1924 Brooklyn death certificate. Her married name was Rachel Kantorowitz (maybe Kantorovich in "Russia). Her maiden was listed as Lutzky. Her daughter, my gg-grandmother, whose married name was Rebecca Lutzky, was the informant. I figured the information was either written down wrong on the death certificate and it was Rebecca's married name, not Rachel's maiden name, or a Lutzky married a Kantorowitz and their daughter married a Lutzky. When a cousin (P. Charney) found me via a post I made on http://www.findagrave.com/, she confirmed the latter. Rebecca married her 1st cousin Solomon/Shlomo Lutzky. My cousin also confirmed that they did marry young, at the age of 14. I had wondered if their ages were misstated on records or if this was the case.
With close cousins marrying there's a risk of genetic defects. Except for some strange family members, me included at times, I have no knowledge of any ailments that can be blamed on DNA being too closely related. One point might be worth mentioning though. Rebecca & Solomon had 10 children. The first 5 were born healthy. Then there's a big gap in ages (8 years) to the next surviving children. I assume this is where the 3 children who didn't survive were born but I have no records or causes of death. The 2 youngest sons were seemingly healthy but both might have been sterile. Neither had children. I don't know if this might be genetics, coincidence, or maybe even this was a side effect of common contagious ailments of the day.