We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Clinical Phenotype and Bone Biopsy Characteristics in a Child with Proteus Syndrome.
- Authors
Al Kaissi, Ali; Misof, Barbara M.; Laccone, Franco; Blouin, Stéphane; Roschger, Paul; Kircher, Susanne G.; Shboul, Mohammad; Mindler, Gabriel T.; Girsch, Werner; Ganger, Rudolf
- Abstract
Proteus syndrome is a rare genetic disorder, which is characterized by progressive, segmental, or patchy overgrowth of diverse tissues of all germ layers, including the skeleton. Here, we present a 9-year-old girl with a somatic-activating mutation (c.49G > A; p.Glu17Lys) in AKT1 gene in a mosaic status typical for Proteus syndrome. She presented with hemihypertrophy of the right lower limb and a "moccasin" lesion among others. A transiliac bone biopsy was analyzed for bone histology/histomorphometry as well as bone mineralization density distribution (BMDD) and osteocyte lacunae sections (OLS) characteristics based on quantitative backscattered electron imaging. Bone histomorphometry revealed highly increased mineralizing surface (Z-score + 2.3) and mineral apposition rate (Z-score + 19.3), no osteoclasts (Z-score − 2.1), and an increased amount of primary bone in the external cortex. BMDD abnormalities included a decreased mode calcium concentration in cancellous bone (Z-score − 1.7) and an increased percentage of highly mineralized cortical bone area (Z-score + 2.4) compared to reference. OLS characteristics showed several differences compared to reference data; among them, there were the highly increased OLS-porosity, OLS-area, and OLS-perimeter on the external cortex (Z-scores + 6.8, + 4.4 and 5.4, respectively). Our findings suggest that increased bone formation reduced matrix mineralization in cancellous bone while the enhanced amount of primary bone in the external cortex increased the portion of highly mineralized cortical bone and caused OLS-characteristics abnormalities. Our results indicate further that remodeling of primary bone might be disturbed or delayed in agreement with the decreased number of osteoclasts observed in this child with Proteus syndrome.
- Subjects
BONE growth; SYNDROMES in children; CANCELLOUS bone; PHENOTYPES; BONE density; COMPACT bone
- Publication
Calcified Tissue International, 2021, Vol 109, Issue 5, p586
- ISSN
0171-967X
- Publication type
Article
- DOI
10.1007/s00223-021-00862-z