Osteogenesis imperfecta, is a genetically and clinically heterogeneous connective tissue disorder that disrupts bone architecture, making it fragile and more prone to fractures. While more than 85% of cases are due to variants in COL1A1 and COL1A2, variants in noncollagen genes have been identified in the remaining cases. The recurring heterozygous variant in IFITM5 (c.-14C>T) leads to osteogenesis imperfecta type V, a second missense variant in IFITM5 (c.119C>T, p.Ser40Leu) leads to phenotype resembling osteogenesis imperfecta type VI. In this report, we describe the first patient with Ser40Trp variant in IFITM5, who presented with multiple fractures in the prenatal period. She remained fracture free after birth (except for trauma-related fractures during puberty) with normal bone mineral densitometry. Her mother, who did not have a history of fracture, was noted to have somatogonadal mosaicism for this variant and became pregnant with a second child with multiple prenatal fractures, found to have the same variant. To our knowledge, this is the first case of somatogonadal mosaicism in IFITM5. In addition, we have summarized the literature on patients presenting with variant in codon 40 (serine) of IFTIM5 protein.

中文翻译：

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患有成骨不全症的家庭的IFITM5中的新型Ser40Trp变体，并复习文献。

成骨不全症是一种遗传和临床上异质的结缔组织疾病，会破坏骨骼结构，使其易碎，更容易发生骨折。尽管超过85％的病例是由于COL1A1和COL1A2的变异引起的，但在其余病例中已鉴定出非胶原基因的变异。IFITM5（c.-14C> T）中反复出现的杂合变异导致V型成骨不全，IFITM5（c.119C> T，p.Ser40Leu）的第二个错义变异导致表型类似于VI型成骨不全。在本报告中，我们描述了IFITM5中首例Ser40Trp变异患者，该患者在产前出现多处骨折。出生后，她保持无骨折（青春期期间与创伤有关的骨折除外），骨密度测定仪正常。她妈妈，没有骨折史的人，据指出对此变体具有体细胞性角膜镶嵌术，并怀有第二个孩子，患有多个产前骨折，发现具有相同的变体。据我们所知，这是IFITM5中第一个体细胞性花叶病。此外，我们总结了有关IFTIM5蛋白第40位密码子（丝氨酸）变异患者的文献。