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Journal of Clinical Medicine Apr 2024: Pycnodysostosis is a rare genetic disorder causing skeletal dysplasia. It is determined by a gene mutation leading to cathepsin K deficiency and predisposes a patient...
: Pycnodysostosis is a rare genetic disorder causing skeletal dysplasia. It is determined by a gene mutation leading to cathepsin K deficiency and predisposes a patient to osteosclerosis, resulting in increased bone fragility. The altered bone quality typical of this disease is responsible for an increased risk of fractures. The purpose of our study was to evaluate the orthopedic manifestations and potential pitfalls in the surgical treatments of pathological fractures in a series of patients treated in our institution who were affected by pycnodysostosis. : We retrospectively evaluated clinical and radiographic characteristics of five patients with pycnodysostosis treated for pathological fractures at our hospital in the past 5 years. : Two male and three female patients were included in this study. Four patients had a family history of pycnodysostosis. All the patients were of short stature, but only two underwent growth hormone treatment. All the patients experienced fractures, mostly in their lower limbs and occurring as a result of low-energy trauma. Most of the patients experienced either consolidation delay or nonunion. : The orthopedic management of fractures in patients with pycnodysostosis poses an ongoing challenge for orthopedic surgeons. The fact that the bone is simultaneously sclerotic and brittle makes any orthopedic surgical treatment challenging and at a high risk of nonunion in any case.
PubMed: 38731051
DOI: 10.3390/jcm13092522 -
Imaging Science in Dentistry Mar 2024Pycnodysostosis (PYCD), an autosomal recessive syndrome, is characterized by an imbalance in bone remodeling that produces various clinical and radiographic craniofacial... (Review)
Review
PURPOSE
Pycnodysostosis (PYCD), an autosomal recessive syndrome, is characterized by an imbalance in bone remodeling that produces various clinical and radiographic craniofacial manifestations. This review represents a systematic examination of these manifestations, as well as oral features associated with PYCD.
MATERIALS AND METHODS
A systematic review was conducted across 8 databases from February to March 2023. The search strategy focused on studies reporting cases of PYCD that examined the clinical and radiographic craniofacial and oral characteristics associated with this syndrome.
RESULTS
The review included 84 studies, encompassing a total of 179 cases of PYCD. More than half of the patients were female (55.3%), and the mean age was 14.7 years. Parental consanguinity was reported in 51.4% of the cases. The most common craniofacial clinical manifestation was a prominent nose, observed in 57.5% of cases. Radiographically, the most frequently reported craniofacial characteristics included the presence of an obtuse mandibular angle (84.3%) and frontal cranial bosses (82.1%). Clinical and radiographic examinations revealed oral alterations, with micrognathia present in 62.6% of patients and malocclusion in 59.2%. Among dental anomalies, tooth agenesis was the most commonly reported, affecting 15.6% of patients.
CONCLUSION
Understanding the clinical and radiographic craniofacial features of PYCD is crucial for dental professionals. This knowledge enables these clinicians to devise effective treatment plans and improve patient quality of life.
PubMed: 38571780
DOI: 10.5624/isd.20230191 -
European Journal of Medical Genetics Feb 2024Pycnodysostosis is an ultra-rare osteosclerotic skeletal disorder characterized by short stature, susceptibly to fractures, acroosteolysis of the distal phalanges, and... (Review)
Review
Pycnodysostosis is an ultra-rare osteosclerotic skeletal disorder characterized by short stature, susceptibly to fractures, acroosteolysis of the distal phalanges, and craniofacial features (frontal bossing, prominent nose, obtuse mandibular angle, micrognathia). Dental abnormalities (delayed eruption of teeth, hypodontia, malocclusion, dental crowding, persistence of deciduous teeth, enamel hypoplasia, and increased caries) are also frequent; due to bone metabolism alteration, the patients have an increased risk for jaw osteomyelitis, especially after tooth extraction or mandible fracture. Other complications are obstructive sleep apnea, endocrine alterations and cytopenia. Pycnodysostosis is caused by biallelic loss of function variants in CTSK gene, coding the lysosomal protease cathepsin K. CTSK is involved in the degradation of bone matrix proteins, such as type I and type II collagen. In pycnodysostosis, this degradation is decreased, leading to increased bone density and bone fragility with pathological fractures and poor healing. We present a clinical report of a female adult patient with typical pycnodysostosis phenotype. At the age of 52 years, she had a pathological spontaneous fracture of the right mandible complicated by osteonecrosis, treated with load bearing osteosynthesis. The direct sequencing of CTSK gene revealed the presence of the pathogenic homozygous variant c.746T>A, (p.Ile249Asn), that confirmed the diagnosis of pycnodysostosis. We also review the literature case series published to date, that suggest to always consider the diagnosis of pycnodysostosis in case of osteosclerosis, even in the absence of brachydactyly or short stature. This report details the natural history of the disease in this patient, from childhood to adulthood, and highlights the importance of a quality of life assessment. In addition, we describe a case of mandibular osteonecrosis and spontaneous fracture in pycnodysostosis, drawing attention on the maxillofacial complications in these patients and on the importance of a personalized follow-up.
Topics: Female; Humans; Middle Aged; Fractures, Spontaneous; Mandible; Mandibular Fractures; Pycnodysostosis; Quality of Life
PubMed: 38141876
DOI: 10.1016/j.ejmg.2023.104904 -
Cureus Sep 2023Introduction Pycnodysostosis is a rare osteosclerotic skeletal dysplasia; its clinical features include short stature, characteristic facial features, increased bone...
Introduction Pycnodysostosis is a rare osteosclerotic skeletal dysplasia; its clinical features include short stature, characteristic facial features, increased bone fragility, and acro-osteolysis of the distal phalanx. Lack of clear guidelines for treatment and follow-up in rare diseases such as pycnodysostosis with growth hormone (GH) deficiency poses a difficulty for the clinician. This study aims to identify clinical, radiological, and endocrine findings of patients with pycnodysostosis focusing on the first year of recombinant human growth hormone (rhGH) treatment response. The eminence of this study is that it presents clinical experience with rhGH, providing an approach for future similar cases. Methods Three girls and two boys from three different families diagnosed with pycnodysostosis via clinical, radiological, and genetic evaluation followed up in the pediatric endocrinology clinic between 2022 and 2023 were enrolled in this study. Clinical findings, anthropometric measurements (weight, height, body mass index [BMI]), and laboratory, radiological, and genetic examinations were evaluated retrospectively. Participants were evaluated for GH deficiency using L-DOPA and clonidine tests if growth rate was below -2 standard deviation score (SDS) for gender and age after one-year follow-up. Results Complaints on admission were short stature (80%) and recurrent bone fractures (20%). Characteristic facial features and brachydactyly were seen in all the patients. Median height SDS on admission was -3.0 (range: -1.9 to -3.8). Median height SDS on last clinic visit was -3.2 (range: -1.7 to -4.2) at a median age of 8 years (range: 3.5-14 years). BMI was normal in four patients, while one was overweight. Bone mineral densitometry z-score was high, and two patients had bone fractures following minor trauma, while one had recurrent fractures. Two siblings (first and second cases) and the third case were diagnosed with GH deficiency, and anterior pituitary hormones were normal otherwise. One had partial empty sella in hypophyseal magnetic resonance imaging. rhGH (33 mcg/kg/day, subcutaneously) was started. Growth rate of the first, second, and third cases increased from 3.3, 3.1, 3.9 to 5, 4.3, 7.2 cm/year, respectively. Prior to rhGH, two had adenoid hypertrophy which was stable following rhGH. Growth rate follow-up of the fourth case continues, while the fifth case, the only participant who has reached adult height, has normal height according to age and gender normative. Conclusion Although rare, pycnodysostosis should not be overlooked in a patient with characteristic facial features, disproportionate short stature, and recurrent fractures. GH deficiency should be evaluated early if growth rate is declining. rhGH may restore growth rate and the possibility of catch-up in growth in patients with pycnodysostosis and GH deficiency. Hence, after first year of rhGH, growth rate of patients with pycnodysostosis is lower when compared to other etiologies of GH deficiency.
PubMed: 37809147
DOI: 10.7759/cureus.44823 -
Frontiers in Oral Health 2023Pycnodysostosis is a skeletal dysplasia characterized by short stature, generalized osteosclerosis, acro-osteolysis, and recognizable facial features. Oral...
Pycnodysostosis is a skeletal dysplasia characterized by short stature, generalized osteosclerosis, acro-osteolysis, and recognizable facial features. Oral manifestations are commonly described and include a high-arched palate with dental crowding and malocclusion, hypoplastic enamel, and retained deciduous teeth with impacted permanent teeth, and there is an increased risk of developing osteomyelitis of the jaw. We report here the history of a 9-year-old male with the typical facial and skeletal phenotype of pycnodysostosis but novel oral features. He presented with bilateral progressive facial swelling, which caused functional impairment with chewing and contributed to his severe obstructive sleep apnea (OSA). The severity of his OSA required surgical intervention, and the lesions were resected. Extensive bone remodeling and replacement by fibrous tissue were noted on submucosal dissection, and bilateral subtotal maxillectomies were required. The histopathology of the biopsied lesion was consistent with a giant cell-rich lesion. Genetic testing identified a pathogenic homozygous variant in the gene, c.953G > A, p. (Cys318Tyr). The proband had a good postsurgical response with sustained improvement in his sleep OSA. We present here the history and clinical characteristics of a patient with typical features of pycnodysostosis and an unusual presentation and histopathology of gnathic bone lesions. This report adds to the body of literature on this rare condition and also highlights the finding of giant cell-rich lesions of the gnathic bones. Giant cell-rich lesions in pycnodysostosis have previously been reported in two cases in the literature. While there is not enough evidence to support a certain association with pycnodysostosis, it is prudent to consider regular oral dental reviews in affected individuals to identify pathology early and avoid such life-threatening complications.
PubMed: 37288425
DOI: 10.3389/froh.2023.1188443 -
JFMS Open Reports 2022A 9-month-old entire male domestic longhair cat presented with a history of pathological fractures, chronic musculoskeletal pain and poor growth. Multiple facial and...
CASE SUMMARY
A 9-month-old entire male domestic longhair cat presented with a history of pathological fractures, chronic musculoskeletal pain and poor growth. Multiple facial and skeletal abnormalities were identified on physical examination and advanced imaging (CT and radiographs). A variant in was identified in the affected cat following whole-exome sequencing (WES). The cat was managed symptomatically with diet, environmental modifications and analgesia.
RELEVANCE AND NOVEL INFORMATION
This is the first report of a cat with a similar clinical presentation and genetic variant to the hereditary human genetic disorder pyknodysostosis. In this case, WES was performed, which often facilitates the diagnosis of various hereditary disorders (ie, a conceptual framework for practicing feline genomic medicine). Despite the severe skeletal and appendicular abnormalities described, the cat was alive more than 2 years after its initial presentation.
PubMed: 36532681
DOI: 10.1177/20551169221137536 -
International Journal of Molecular... Nov 2022Cathepsin K (CatK) is a part of the family of cysteine proteases involved in many important processes, including the degradation activity of collagen 1 and elastin in... (Review)
Review
Cathepsin K (CatK) is a part of the family of cysteine proteases involved in many important processes, including the degradation activity of collagen 1 and elastin in bone resorption. Changes in levels of CatK are associated with various pathological conditions, primarily related to bone and cartilage degradation, such as pycnodysostosis (associated with CatK deficiency), osteoporosis, and osteoarthritis (associated with CatK overexpression). Recently, the increased secretion of CatK is being highly correlated to vascular inflammation, hypersensitivity pneumonitis, Wegener granulomatosis, berylliosis, tuberculosis, as well as with tumor progression. Due to the wide spectrum of diseases in which CatK is involved, the design and validation of active site-specific inhibitors has been a subject of keen interest in pharmaceutical companies in recent decades. In this review, we summarized the molecular background of CatK and its involvement in various diseases, as well as its clinical significance for diagnosis and therapy.
Topics: Cathepsin K; Collagen Type I; Bone and Bones; Cysteine Proteases
PubMed: 36430239
DOI: 10.3390/ijms232213762 -
Clinical Case Reports Nov 2022We describe a case in which a 41-year-old pregnant female with pycnodysostosis presented for elective cesarean section at week 37 + 5 of pregnancy. This is the first...
We describe a case in which a 41-year-old pregnant female with pycnodysostosis presented for elective cesarean section at week 37 + 5 of pregnancy. This is the first reported case of pycnodysostosis during pregnancy in Oman, to the author's best knowledge.
PubMed: 36381044
DOI: 10.1002/ccr3.6565 -
Indian Journal of Orthopaedics Aug 2022Atypical subtrochanteric femoral fractures are a common problem associated with pycnodysostosis. Pycnodysostosis is a rare sclerotic bone disease caused by a mutation in...
ABSTRACT
Atypical subtrochanteric femoral fractures are a common problem associated with pycnodysostosis. Pycnodysostosis is a rare sclerotic bone disease caused by a mutation in the cathepsin K gene. Fracture healing in pycnodysostosis cases is typically inferior. Here, we report a case of bilateral atypical subtrochanteric femoral fractures in one patient with pycnodysostosis. The right subtrochanteric fracture was treated with open reduction and internal fixation (open plating), and united through primary bone healing, while the left one was treated with closed reduction and internal fixation (submuscular plating), and united through secondary bone healing. Although the time to bony union was delayed, fracture union after extramedullary osteosynthesis was obtained in both atypical fractures, demonstrating that both primary and secondary bone healing is possible in patients with pycnodysostosis.
LEVEL OF CLINICAL EVIDENCE
4.
PubMed: 35928669
DOI: 10.1007/s43465-022-00675-8