Raine Syndrome (RS) is caused by biallelic loss-of-function mutations in FAM20C gene and characterized by hypophosphatemia, typical facial and skeletal features. Subperiosteal bone formation and generalized osteosclerosis are the most common radiological findings. Here we present a new case with RS. A 9-month-old male patient on a home-type ventilator was referred for hypophosphatemia. He was born with a weight of 3800 g to non-consanguineous parents. Prenatal ultrasound had demonstrated nasal bone agenesis. A large anterior fontanel, frontal bossing, exophthalmos, hypoplastic nose, high arched palate, low set ears, triangular mouth, and corneal opacification were detected on physical examination. Serial skeletal X-rays revealed diffuse osteosclerosis at birth which was gradually decreased by the age of 5 months with subperiosteal undermineralized bone formation and medullary space of long bone could be distinguishable with bone-within-a-bone appearance. At 9 months of age, hand X-ray revealed cupping of the ulna with loose radial bone margin with minimal fraying and osteopenia. Cranial computed tomography scan showed bilateral periventricular calcification and hydrocephalus in progress. The clinical, laboratory, and radiological examinations were consistent with RS. Molecular analyses revealed a compound heterozygous mutation in FAM20C gene (a known pathogenic mutation, c.1645C > T, p.Arg549Trp; and a novel c.863 + 5 G > C variant). The patient died due to respiratory failure at 17 months of age. This case allowed us to demonstrate natural progression of skeletal features in RS. Furthermore, we have described a novel FAM20C variant causing RS. Previous literature on RS is also reviewed.

中文翻译：

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低磷血症的罕见原因：Raine 综合征随着年龄的增长而改变临床特征。

Raine 综合征 (RS) 是由 FAM20C 基因的双等位基因功能丧失突变引起的，其特征是低磷血症、典型的面部和骨骼特征。骨膜下骨形成和全身性骨硬化是最常见的放射学表现。在这里，我们提出了一个新的 RS 案例。一名使用家用呼吸机的 9 个月大男性患者因低磷血症被转诊。他出生时体重为 3800 克，父母为非近亲。产前超声显示鼻骨发育不全。体格检查发现前囟、前额凸出、眼球突出、鼻发育不全、高拱形上颚、低位耳朵、三角口和角膜混浊。系列骨骼 X 线片显示出生时弥漫性骨硬化，到 5 个月大时逐渐减轻，骨膜下骨质疏松，长骨髓腔可与骨内骨相区分。在 9 个月大时，手部 X 光片显示尺骨呈拔罐状，桡骨边缘松散，磨损和骨质减少最少。头颅计算机断层扫描显示双侧脑室周围钙化和脑积水进展。临床、实验室和放射学检查与 RS 一致。分子分析揭示了 FAM20C 基因中的复合杂合突变（已知的致病突变，c.1645C > T，p.Arg549Trp；和新的 c.863 + 5 G > C 变体）。患者在 17 个月大时因呼吸衰竭死亡。这个案例使我们能够展示 RS 中骨骼特征的自然进展。此外，我们描述了一种导致 RS 的新型 FAM20C 变体。还回顾了以前关于 RS 的文献。