{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,27]],"date-time":"2025-10-27T10:34:50Z","timestamp":1761561290044,"version":"build-2065373602"},"reference-count":21,"publisher":"BMJ","issue":"10","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J Med Genet"],"published-print":{"date-parts":[[1993,10]]},"abstract":"<jats:p>It has been suggested that neural tube defects (NTDs) of the upper type (anencephaly, encephalocele, and thoracic spina bifida) may have a pathogenesis different from those of the lower type (lumbosacral spina bifida), since recurrent cases within a sibship were said always to be concordant with respect to NTD type. Also, spontaneous abortion, additional malformation, and recurrence rate were observed to be higher in the upper group, and there was an excess of females in upper NTD probands. To test this hypothesis, we measured the above variables in upper and lower NTDs in a sample from Quebec. We found less than full concordance (50%) of NTD type in 18 sib pairs. Recurrence rate was not significantly lower in the lower NTD group (5.6 v 5.8%). The other variables were in general agreement with previous studies, inconsistent findings possibly attributable to different NTD population incidences. These findings can be accounted for if upper and lower NTDs share a similar pathogenesis and the embryo is more susceptible during early than late neural tube formation.<\/jats:p>","DOI":"10.1136\/jmg.30.10.849","type":"journal-article","created":{"date-parts":[[2008,11,10]],"date-time":"2008-11-10T15:23:16Z","timestamp":1226330596000},"page":"849-851","source":"Crossref","is-referenced-by-count":18,"title":["Upper and lower neural tube defects: an alternate hypothesis."],"prefix":"10.1136","volume":"30","author":[{"given":"B H","family":"Garabedian","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"F C","family":"Fraser","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[1993,10,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1002\/ajmg.1320210103","article-title":"Possible causal heterogeneity in spina bifida cystica","volume":"21","author":"Toriello, H.V.; Higgins, J.V.","year":"1985","unstructured":"Toriello HV, Higgins JV. Possible causal heterogeneity in spina bifida cystica. Am J Med Genet 1985;21:13-20.","journal-title":"Am J Med Genet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"363","DOI":"10.1016\/0301-0082(90)90037-H","article-title":"The embryonic development of mammalian neural tube defects","volume":"35","author":"Copp, A.J.; Brook, F.A.; Estibeiro, P.; Shum, A.S.W.; Cockcroft, D.L.","year":"1990","unstructured":"Copp AJ, Brook FA, Estibeiro P, Shum ASW, Cockcroft DL. The embryonic development of mammalian neural tube defects. Prog Neurobiol 1990;35:363-403.","journal-title":"Prog Neurobiol"},{"key":"ref_3","first-page":"827","article-title":"Clinical, genetic, and epidemiological factors in neural tube defects","volume":"43","author":"Hall, J.G.; Friedman, J.M.; Kenna, B.A.; Popkin, J.; Jawanda, M.; Arnold, W.","year":"1988","unstructured":"Hall JG, Friedman JM, Kenna BA, Popkin J, Jawanda M, Arnold W. Clinical, genetic, and epidemiological factors in neural tube defects. Am J Hum Genet 1988;43:827-37.","journal-title":"Am J Hum Genet"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"699","DOI":"10.1002\/ajmg.1320260325","article-title":"Neural tube defects and sex ratios","volume":"26","author":"Seller, M.J.","year":"1987","unstructured":"Seller MJ. Neural tube defects and sex ratios. Am J Med Genet 1987;26:699-707.","journal-title":"Am J Med Genet"},{"key":"ref_5","first-page":"54","article-title":"Normal and abnormal development of the human nervous system","author":"Lemire, R.J.; Loeser, J.D.; Leech, R.W.; Alvord, E.C.","year":"1975","unstructured":"Lemire RJ, Loeser JD, Leech RW, Alvord EC. Normal and abnormal development of the human nervous system. New York: Harper and Row, 1975:54-83."},{"key":"ref_6","first-page":"94","article-title":"Is anencephaly a single entity? A brief note on the morphologic heterogeneity of anencephaly","volume-title":"The nervous system","volume":"1","author":"McCormick, W.F.","year":"1971","unstructured":"McCormick WF. Is anencephaly a single entity? A brief note on the morphologic heterogeneity of anencephaly. In: Bergsma D, ed. The nervous system. New York: Alan R Liss for the National Foundation - March of Dimes. Birth Defects 1971;VII(1):94-6."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"538","DOI":"10.1093\/oxfordjournals.aje.a113335","article-title":"Etiologic heterogeneity of neural tube defects: clues from epidemiology","volume":"115","author":"Khoury, M.J.; Erickson, J.D.; James, L.M.","year":"1982","unstructured":"Khoury MJ, Erickson JD, James LM. Etiologic heterogeneity of neural tube defects: clues from epidemiology. Am J Epidemiol 1982;115:538-48.","journal-title":"Am J Epidemiol"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1002\/ajmg.1320250612","article-title":"Neural tube defects: heterogeneity and homogeneity","volume":"2","author":"Seller, M.J.; Kalousek, D.K.","year":"1986","unstructured":"Seller MJ, Kalousek DK. Neural tube defects: heterogeneity and homogeneity. Am J Med Genet 1986;suppl 2:77-87.","journal-title":"Am J Med Genet"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"547","DOI":"10.1002\/tera.1420440508","article-title":"Heterogeneity of neural tube defects in Europe: the significance of site of defect and presence of other major anomalies in relation to geographic differences in prevalence","volume":"44","author":"Dolk, H.; De Wals, P.; Gillerot, Y.","year":"1991","unstructured":"Dolk H, De Wals P, Gillerot Y, et al. Heterogeneity of neural tube defects in Europe: the significance of site of defect and presence of other major anomalies in relation to geographic differences in prevalence. Teratology 1991;44:547-59.","journal-title":"Teratology"},{"key":"ref_10","article-title":"Medicalgenetics: principles andpractice","author":"Nora, J.J.; Fraser, F.C.","year":"1989","unstructured":"Nora JJ, Fraser FC. Medicalgenetics: principles andpractice. 3rd ed. Philadelphia: Lea & Febiger, 1989.","edition":"3rd ed"},{"issue":"100","key":"ref_11","first-page":"748","article-title":"Anencephaly and spina bifida in the province of Quebec","volume":"1969","author":"Horowitz, I.; McDonald, A.D.","unstructured":"Horowitz I, McDonald AD. Anencephaly and spina bifida in the province of Quebec. Can Med Assoc J 1969;100:748-55.","journal-title":"Can Med Assoc J"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1002\/ajmg.1320030409","article-title":"Sib risks of anencephaly and spina bifida in British Columbia","volume":"3","author":"McBride, M.L.","year":"1979","unstructured":"McBride ML. Sib risks of anencephaly and spina bifida in British Columbia. Am J Med Genet 1979;3:377-87.","journal-title":"Am J Med Genet"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1002\/ajmg.1320390233","article-title":"Are the neurulation and canalization forms of neural tube defects causally distinct?","volume":"39","author":"Torok 0, Papp Z","year":"1991","unstructured":"Torok 0, Papp Z. Are the neurulation and canalization forms of neural tube defects causally distinct? Am J Med Genet 1991;39:241.","journal-title":"Am J Med Genet"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"503","DOI":"10.1136\/jmg.25.7.503-a","article-title":"Are 'upper' and 'lower' neural tube defects aetiologically different?","volume":"25","author":"Frecker, M.F.; Fraser, F.C.; Heneghan, W.D.","year":"1988","unstructured":"Frecker MF, Fraser FC, Heneghan WD. Are 'upper' and 'lower' neural tube defects aetiologically different? J Med Genet 1988;25:503-4.","journal-title":"J Med Genet"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"605","DOI":"10.1136\/jmg.28.9.605","article-title":"Do familial neural tube defects breed true?","volume":"28","author":"Drainer, E.; May, H.M.; Tolmie, J.L.","year":"1991","unstructured":"Drainer E, May HM, Tolmie JL. Do familial neural tube defects breed true? J Med Genet 1991;28:605-8.","journal-title":"J Med Genet"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"394","DOI":"10.1002\/ajmg.1320350316","article-title":"Neural tube defects: are neurulation and canalization forms causally distinct?","volume":"35","author":"Seller, M.J.","year":"1990","unstructured":"Seller MJ. Neural tube defects: are neurulation and canalization forms causally distinct? Am J Med Genet 1990;35:394-6.","journal-title":"Am J Med Genet"},{"key":"ref_17","first-page":"1","article-title":"Spontaneous abortion risks in man: data from reproductive histories collected in a medical genetics unit","volume":"16","author":"Warburton, D.; Fraser, F.C.","year":"1964","unstructured":"Warburton D, Fraser FC. Spontaneous abortion risks in man: data from reproductive histories collected in a medical genetics unit. Am J Hum Genet 1964;16:1-25.","journal-title":"Am J Hum Genet"},{"key":"ref_18","first-page":"35561","article-title":"Epidemiological studies of neural tube defects in Newfoundland","volume":"36","author":"Frecker, M.; Fraser, F.C.","year":"1987","unstructured":"Frecker M, Fraser FC. Epidemiological studies of neural tube defects in Newfoundland. Teratology 1987;36:35561.","journal-title":"Teratology"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1530\/jrf.0.0790159","article-title":"Sex difference in mouse embryonic development at neurulation","volume":"79","author":"Seller, M.J.; Perkins-Cole, K.J.","year":"1987","unstructured":"Seller MJ, Perkins-Cole KJ. Sex difference in mouse embryonic development at neurulation. J Reprod Fertil 1987;79:159-61.","journal-title":"J Reprod Fertil"},{"key":"ref_20","first-page":"413","article-title":"The development of the human brain, the closure of the caudal neuropore, and the beginning of secondary neurulation at stage 12","volume-title":"Anat Embryol","volume":"176","author":"Muller, F.; O'Rahilly, R.","year":"1987","unstructured":"Muller F, O'Rahilly R. The development of the human brain, the closure of the caudal neuropore, and the beginning of secondary neurulation at stage 12. Anat Embryol 1987;176:413-30."},{"key":"ref_21","first-page":"871","article-title":"Sex ratios in neural tube defects","volume":"ii:","author":"ML, Martinez Frias; JA, Parralo; J, Salvador; JL, Frias","year":"1986","unstructured":"Martinez Frias ML, Parralo JA, Salvador J, Frias JL. Sex ratios in neural tube defects. Lancet 1986;ii:871-2.","journal-title":"Lancet"}],"container-title":["Journal of Medical Genetics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/jmg.30.10.849","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,17]],"date-time":"2025-10-17T17:10:41Z","timestamp":1760721041000},"score":1,"resource":{"primary":{"URL":"https:\/\/jmg.bmj.com\/lookup\/doi\/10.1136\/jmg.30.10.849"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1993,10]]},"references-count":21,"journal-issue":{"issue":"10","published-online":{"date-parts":[[1993,10,1]]},"published-print":{"date-parts":[[1993,10]]}},"alternative-id":["10.1136\/jmg.30.10.849"],"URL":"https:\/\/doi.org\/10.1136\/jmg.30.10.849","relation":{},"ISSN":["0022-2593","1468-6244"],"issn-type":[{"type":"print","value":"0022-2593"},{"type":"electronic","value":"1468-6244"}],"subject":[],"published":{"date-parts":[[1993,10]]}}}