Tsuboi T, Endo S
Tokyo Health Center for Izu- and Ogasawara Islands, Tokyo Metropolitan Bureau of Public Health, Japan.
Epilepsy Res Suppl. 1991;4:119-28.
Children with febrile convulsions (FC) including 46 twin pairs, 1913 families including 393 sibling pairs, and 42 three-generation FC kindreds have been studied. Twin studies: (1) The pairwise concordance rate for FC was 69% (18/26 pairs) in monozygotic (MZ) and 20% (4/20 pairs) in dizygotic (DZ) twins (P less than 0.01). (2) The intra-pair similarity of clinical symptoms in 18 concordant MZ twin pairs showed a positive significant correlation, particularly in 4 items--duration of seizure, exogenous factors, intelligence level, and background EEG abnormality. These correlations were greater than those in sibling pairs. (3) No evident cause for discordance was detected in 8 discordant MZ twin pairs, and many dissimilar symptoms were observed in 4 concordant DZ twin pairs. Sibship studies: A large positive correlation of some clinical symptoms was observed in sibling pairs concordant for FC: age at onset of FC, degree of fever, duration of seizure, exogenous factors, and background EEG abnormality (r = +0.2- +0.6). Family history analysis: Morbidity risk among near relatives (17% in parents, 23% in siblings) than in second- (6.1%) or third-degree relatives (4.6%). The difference was found between: sibling greater than parents, uncles greater than aunts, male cousins greater than female cousins. Segregation analysis showed maternal preponderance. In 42 three-generation kindreds the morbidity risk was higher in siblings (32%), uncles/aunts (14%), and cousins (6.4%) than in relatives of other probands. Characteristic findings in FC patients with family history: Characteristic findings in FC patients with an FC parent or sibling, compared with those with no family history, were early onset of FC, lower degree of fever, longer duration of seizure, many recurrences, FC recurrence after age 3, and background EEG abnormality. Similar findings were more markedly observed in 42 3-generation kindreds. Mode of inheritance: A multifactorial mode of inheritance for FC receives some support from this study, and the heritability was estimated as 75%.
对患有热性惊厥（FC）的儿童进行了研究，其中包括46对双胞胎、1913个家庭（含393对同胞兄弟姐妹）以及42个三代FC家系。双胞胎研究：（1）单卵双生子（MZ）中FC的成对一致率为69%（26对中的18对），双卵双生子（DZ）中为20%（20对中的4对）（P<0.01）。（2）18对一致的MZ双胞胎对中临床症状的对内相似性呈显著正相关，尤其是在4项指标上——惊厥持续时间、诱发因素、智力水平和背景脑电图异常。这些相关性高于同胞兄弟姐妹对。（3）在8对不一致的MZ双胞胎对中未检测到明显的不一致原因，在4对一致的DZ双胞胎对中观察到许多不同的症状。同胞研究：在FC一致的同胞对中观察到一些临床症状存在较大的正相关：FC发病年龄、发热程度、惊厥持续时间、诱发因素和背景脑电图异常（r=+0.2至+0.6）。家族史分析：近亲中的发病风险（父母为17%，兄弟姐妹为23%）高于二级亲属（6.1%）或三级亲属（4.6%）。发现差异存在于：兄弟姐妹高于父母，叔叔高于阿姨，男性表亲高于女性表亲。分离分析显示母系优势。在42个三代家系中，同胞（32%）、叔叔/阿姨（14%）和表亲（6.4%）的发病风险高于其他先证者的亲属。有家族史的FC患者的特征性发现：与无家族史的FC患者相比，有FC父母或兄弟姐妹的FC患者的特征性发现为FC发病早、发热程度低、惊厥持续时间长、复发次数多、3岁后FC复发以及背景脑电图异常。在42个三代家系中更明显地观察到类似发现。遗传方式：本研究为FC的多因素遗传方式提供了一些支持，遗传度估计为75%。
