背景：加德纳综合征是一种罕见的遗传性癌症易感性疾病，以肠息肉、多发性骨瘤、软硬组织肿瘤为特征。大约 30%-70% 的加德纳综合征患者存在牙齿异常，并且可以在常规牙科检查中发现。然而，有时由于临床变异性高和临床情况不完整，诊断具有挑战性。在此，我们报告了一个患有各种牙齿和骨骼异常的家庭，在基于最先进的下一代测序技术的全面遗传分析的帮助下，确定了明确的诊断。病例介绍：一名 17 岁女性指标患者出现牙齿问题（龋齿、阻生牙、滞留牙和前牙）以及与加德纳综合征不相似的非典型骨异常。由于全景 X 射线发现非典型骨骼异常，她在 11 岁时首次被转诊至我们的遗传咨询部门。 3.6 号牙齿被手术切除，组织病理学报告显示下颌骨存在类似佩吉特病的骨代谢紊乱，具有混合的成骨细胞和破骨细胞活性。体检发现腰部皮下有一个小肿瘤。肿瘤的超声检查提出了软骨瘤病软组织传播的可能性。她的妹妹比她小两岁，14 岁，患有一些良性肿瘤（多发性外生骨疣、牙瘤、表皮样囊肿）和阻生牙。他们的母亲也有骨骼症状。她的下牙没有发育，第 9-10 肋骨融合，她抱怨间歇性下颌疼痛。颅骨 CT 扫描显示颅骨纤维异常增生。全外显子组测序鉴定出索引患者 DNA 中 APC 基因存在杂合致病性无义突变 (c.4700C>G；p.Ser1567*)。靶向测序显示其他受影响的家庭成员（姐姐和母亲）的 DNA 中也存在相同的变异。结论：这种罕见的、由基因决定的综合征的早期诊断非常重要，因为肠息肉恶变的可能性很高。牙医应该熟悉这种疾病的典型颌面特征，以便能够将患者转介至遗传咨询。牙齿异常通常先于肠息肉病出现，有助于早期诊断，从而增加患者的生存机会。对于具有非典型表型体征的患者可能需要进行遗传分析。版权所有 © 2024 Antal、Zsigmond、Till、Orsi、Szanto、Büki、Kereskai、Herbert、Hadzsiev 和 Bene。

Background: Gardner syndrome is a rare genetic cancer predisposition disorder characterized by intestinal polyposis, multiple osteomas, and soft and hard tissue tumors. Dental anomalies are present in approximately 30%-70% of patients with Gardner syndrome and can be discovered during routine dental examinations. However, sometimes the diagnosis is challenging due to the high clinical variability and incomplete clinical picture. Herein, we report a family with various dental and bone anomalies, in which the definitive diagnosis was established with the help of a comprehensive genetic analysis based on state-of-the-art next-generation sequencing technology. Case presentation: A 17-year-old female index patient presented with dental (caries, impacted, retained and anteriorly located teeth) and atypical bone anomalies not resembling Gardner syndrome. She was first referred to our Genetic Counselling Unit at the age of 11 due to an atypical bone abnormality identified by a panoramic X-ray. Tooth 3.6 was surgically removed and the histopathology report revealed a Paget's disease-like bone metabolic disorder with mixed osteoblastic and osteoclastic activity of the mandible. A small lumbar subcutaneous tumor was discovered by physical examination. Ultrasound examination of the tumor raised the possibility of a soft tissue propagation of chondromatosis. Her sister, 2 years younger at the age of 14, had some benign tumors (multiple exostoses, odontomas, epidermoid cysts) and impacted teeth. Their mother had also skeletal symptoms. Her lower teeth did not develop, the 9th-10th ribs were fused, and she complained of intermittent jaw pain. A cranial CT scan showed fibrous dysplasia on the cranial bones. Whole exome sequencing identified a heterozygous pathogenic nonsense mutation (c.4700C>G; p.Ser1567*) in the APC gene in the index patient's DNA. Targeted sequencing revealed the same variant in the DNA of the other affected family members (the sister and the mother). Conclusion: Early diagnosis of this rare, genetically determined syndrome is very important, because of the potentially high malignant transformation of intestinal polyps. Dentists should be familiar with the typical maxillofacial features of this disorder, to be able to refer patients to genetic counseling. Dental anomalies often precede the intestinal polyposis and facilitate the early diagnosis, thereby increasing the patients' chances of survival. Genetic analysis may be necessary in patients with atypical phenotypic signs.Copyright © 2024 Antal, Zsigmond, Till, Orsi, Szanto, Büki, Kereskai, Herbert, Hadzsiev and Bene.