Abstract：
BACKGROUND: Progressive osseous heteroplasia (POH) is a rare genetic condition that causes progressive ossification. This usually results from an inactivating mutation of the paternal GNAS gene. Herein, we report a case of POH caused by a novel mutation in exon 2 of the GNAS gene.
METHODS: A 5-year-old Chinese boy was referred to our hospital for a growing mass in his right foot. Although laboratory findings were normal, radiographic imaging revealed severe ossification in his right foot and smaller areas of intramuscular ossification in his arms and legs. A de novo mutation (c.175C > T, p.Q59X) in exon 2 of the GNAS gene was identified, prompting a diagnosis of POH. We conducted a systematic literature review to better understand this rare disease.
CONCLUSIONS: We have discovered that a de novo nonsense mutation in exon 2 of GNAS can lead to POH. Our literature review revealed that ankylosis of the extremities is the primary clinical outcome in patients with POH. Unlike other conditions such as fibrodysplasia ossificans progressiva (FOP), patients with POH do not experience respiratory failure. However, much remains to be learned about the relationship between the type of GNAS gene mutation and the resulting POH symptoms. Further research is needed to understand this complex and rare disease. This case adds to our current understanding of POH and will contribute to future studies and treatments.
METHODS: A 5-year-old Chinese boy was referred to our hospital for a growing mass in his right foot. Although laboratory findings were normal, radiographic imaging revealed severe ossification in his right foot and smaller areas of intramuscular ossification in his arms and legs. A de novo mutation (c.175C > T, p.Q59X) in exon 2 of the GNAS gene was identified, prompting a diagnosis of POH. We conducted a systematic literature review to better understand this rare disease.
CONCLUSIONS: We have discovered that a de novo nonsense mutation in exon 2 of GNAS can lead to POH. Our literature review revealed that ankylosis of the extremities is the primary clinical outcome in patients with POH. Unlike other conditions such as fibrodysplasia ossificans progressiva (FOP), patients with POH do not experience respiratory failure. However, much remains to be learned about the relationship between the type of GNAS gene mutation and the resulting POH symptoms. Further research is needed to understand this complex and rare disease. This case adds to our current understanding of POH and will contribute to future studies and treatments.
摘要：
背景：进行性骨异型增生（POH）是一种罕见的遗传病，可导致进行性骨化。这通常是由父系GNAS基因的失活突变引起的。在这里，我们报道了一例由GNAS基因第2外显子新突变引起的POH病例。
方法：一名5岁的中国男孩因右脚肿块增大而被转诊到我们医院。虽然实验室检查结果正常,影像学检查显示，他的右脚严重骨化，胳膊和腿的肌肉骨化区域较小。从头突变（c.175C>T，p.Q59X）在GNAS基因的外显子2中进行了鉴定，提示POH的诊断。为了更好地了解这种罕见疾病，我们进行了系统的文献综述。
结论：我们发现GNAS第2外显子的从头无义突变可导致POH。我们的文献综述显示，四肢强直是POH患者的主要临床结局。不像其他条件，如纤维化骨化性进展（FOP），POH患者不会出现呼吸衰竭。然而,关于GNAS基因突变的类型与所产生的POH症状之间的关系还有很多待了解。需要进一步的研究来了解这种复杂而罕见的疾病。这个案例增加了我们目前对POH的理解，并将有助于未来的研究和治疗。
方法：一名5岁的中国男孩因右脚肿块增大而被转诊到我们医院。虽然实验室检查结果正常,影像学检查显示，他的右脚严重骨化，胳膊和腿的肌肉骨化区域较小。从头突变（c.175C>T，p.Q59X）在GNAS基因的外显子2中进行了鉴定，提示POH的诊断。为了更好地了解这种罕见疾病，我们进行了系统的文献综述。
结论：我们发现GNAS第2外显子的从头无义突变可导致POH。我们的文献综述显示，四肢强直是POH患者的主要临床结局。不像其他条件，如纤维化骨化性进展（FOP），POH患者不会出现呼吸衰竭。然而,关于GNAS基因突变的类型与所产生的POH症状之间的关系还有很多待了解。需要进一步的研究来了解这种复杂而罕见的疾病。这个案例增加了我们目前对POH的理解，并将有助于未来的研究和治疗。
