Kelani A B, Moumouni H, Issa A W, Younsaa H, Fokou Hmu, Sani R, Sanoussi S, Denholm L J, Beever J E, Catala M
Département de Chirurgie, Faculté des Sciences de la Santé (FSS), Université Abdou Moumouni (UAM), Niamey, Niger.
Service de Neurochirurgie, Hôpital National, Niamey, Niger.
Childs Nerv Syst. 2017 Mar;33(3):529-534. doi: 10.1007/s00381-017-3337-x. Epub 2017 Jan 12.
Notomelia associated with neural tube defects are rare diseases.
A baby was born in Niger with multiple congenital embryonic malformations on the posterior midline. The most rostral malformation was an accessory limb (polymelia) at the level of the lumbar vertebrae composed of two long bones, a foot and three toes. Accessory male genitalia were present at the base of this malformed accessory limb which had no apparent motor or sensory innervation. The second malformation was a sacral vestigial appendage with an adjacent dermal sinus opening onto the posterior midline and extending internally to the dura through a defect of the vertebral arches. From the published literature and this particular case, we conclude that notomelia is a rare clinical sequela of a neural tube defect (NTD) and is correctly classified as a dysraphic appendage.
The recent occurrence of three similar cases in the same ethnic group from Niger, three from consanguineous parents, suggests that genetic factors are likely to contribute significantly to the genesis of this syndrome, consistent with a recent report that mutation of the bovine NHLRC2 gene resulting in a V311A substitution at a highly conserved locus in the NHLRC2 protein is, when homozygous, causally associated with several forms of polymelia including notomelia, with heteropagus conjoined twinning and with other NTD-related embryonic malformations. Detailed genome-wide studies of children with dysraphic appendages are indicated.
与神经管缺陷相关的下肢旁侧肢体畸形是罕见疾病。
一名婴儿在尼日尔出生，后正中线存在多种先天性胚胎畸形。最靠上的畸形是腰椎水平的一个附属肢体（多指/趾畸形），由两根长骨、一只脚和三个脚趾组成。在这个畸形附属肢体的基部存在附属男性生殖器，该附属肢体没有明显的运动或感觉神经支配。第二个畸形是一个骶部残留附属物，伴有一个相邻的皮样窦，开口于后正中线，并通过椎弓缺损向内延伸至硬脑膜。从已发表的文献和这个特殊病例来看，我们得出结论，下肢旁侧肢体畸形是神经管缺陷（NTD）的一种罕见临床后遗症，并且正确地归类为脊柱裂附属物。
最近在来自尼日尔的同一族群中出现了三例类似病例，其中三例来自近亲父母，这表明遗传因素可能对该综合征的发生有显著贡献，这与最近的一份报告一致，即牛NHLRC2基因的突变导致NHLRC2蛋白高度保守位点的V311A替代，当纯合时，与包括下肢旁侧肢体畸形在内的几种多指/趾畸形形式、寄生连体双胎以及其他与NTD相关的胚胎畸形有因果关系。需要对患有脊柱裂附属物的儿童进行详细的全基因组研究。
