ESPE2024 Poster Category 2 Bone, Growth Plate and Mineral Metabolism (31 abstracts)
1Afyonkarahisar Health Sciences University Faculty of Medicine, Department of Pediatric Endocrinology, Afyonkarahisar, Turkey. 2Erciyes University Faculty of Medicine, Department of Pediatric Endocrinology, Kayseri, Turkey. 3Ege University Faculty of Medicine, Department of Pediatric Endocrinology, İzmir, Turkey. 4Dr Sami Ulus Child Health and Diseases Health Application and Research Center, Department of Pediatric Endocrinology, Ankara, Turkey. 5Pamukkale University Faculty of Medicine, Department of Pediatric Endocrinology, Denizli, Turkey. 6Başakşehir Çam and Sakura City Hospital, Department of Pediatric Endocrinology, İstanbul, Turkey. 7Sancaktepe Şehit Prof. Dr. İlhan Varank Training and Research Hospital, Department of Pediatric Endocrinology, İstanbul, Turkey. 8Ege University Faculty of Medicine, Department of Pediatric Genetics, İzmir, Turkey
Introduction-Aim: Aggrecan, encoded by the ACAN gene; is a cartilage- specific proteoglycan- containing protein that is densely found in the growth plate and intervertebral discs. Heterozygous variants have been reported in cases with short stature, mild skeletal dysplasia, and advanced bone age. The Aim of this study is to examine the phenotypic characteristics of pediatric cases with ACAN gene variants in Turkey.
Material-Method: Children who applied with complaints of short stature and whose ACAN gene variant was detected in genetic analysis were included retrospectively. Anthropometric data, dysmorphic findings, bone age and genetic analysis results of the cases were examined.
Results: A total of 15 pediatric cases from 6 centers participating in the study were evaluated. Eight (53.3%) of the cases were female and 7 (46.7%) were male. The median age at presentation was 4 (0.5;11) years. While the median admission height SDS of the cases was -2.6 (-6.3; -1.1), one case was pubertal and 14 cases were prepubertal. When accompanying dysmorphic findings are examined; frontal prominence, flattened nasal root, low nuchal hairline, nipple separation, brachydactyly, anteverted ears and pectus excavatum was detected (Table-1). Advanced bone age at presentation was detected in 8 (53.3%) cases. There was a family history of short stature in 13 (86.6%) cases, but segregation was performed in 5 of these cases. When the variant analyzes were examined, the variant detected in one case was homozygous, while the other cases were heterozygous (Table-2). Homozygous variant was shown in the case with the most severe short stature (-6.3 SDS).
Number | Age (years) | Bone age (years) | Height SDS |
1 | 4.2 | 7.9 | -2.79 |
2 | 5.7 | 7 | -2.4 |
3 | 3.9 | 4 | -2.7 |
4 | 9.2 | 8 | -2.6 |
5 | 5.2 | 5 | -6.34 |
6 | 3.2 | 4 | -2.98 |
7 | 5.4 | 5 | -3.33 |
8 | 5 | 5.5 | -1.6 |
9 | 1.9 | 2.5 | -3.6 |
10 | 11.9 | 13.5 | -1.14 |
11 | 1.9 | 2.5 | -3.38 |
12 | 7.6 | 8.5 | -2.03 |
13 | 8.7 | 10.5 | -1.21 |
14 | 5.3 | 4.5 | -1.94 |
15 | 3.4 | 3.5 | -1.76 |
Conclusion: Aggrecanopathy/aggrecan related dysplasias are one of the skeletal dysplasias that cause short stature. In these cases, height is variable and there is usually a family history. Contrary to popular belief, advanced bone age and osteoarticular complications are not mandatory and cannot be demonstrated in every case. ACAN gene mutations should also be considered in the differential diagnosis of cases with familial short stature. Detailed genetic studies are needed to elucidate the pathogenic mechanisms of these variants.