The Age Dependent Progression of Hajdu-Cheney Syndrome in Two Families

First case of Hajdu-Cheney syndrome in Lithuania caused by novel NOTCH2 gene likely pathogenic variant

Hajdu-Cheney syndrome (HCS) is an extremely rare autosomal dominant skeletal disorder. The prevalence rate of less than 1 case per 1,000,000 newborns and only 50 cases were reported in the medical literature. HCS is characterized by progressive bone resorption in the distal phalanges (acro-osteolysis), progressive osteoporosis, distinct craniofacial changes, dental anomalies, and occasional association with renal abnormalities. HCS is caused by pathogenic variants in the NOTCH2 gene, 34th exon. We report first familial case of HCS caused by likely pathogenic variant of NOTCH2 gene c.6449delC, p.(Pro2150LeufsTer5).

Hajdu-Cheney syndrome with a novel variant in NOTCH2 gene: A case report

Introduction

Hajdu-Cheney syndrome is a rare disorder caused by truncation mutations in exon 34 of the NOTCH2 gene. The main presentation includes acro-osteolysis, osteoporosis, and dysmorphism. This syndrome affects the other body systems as well.

Case presentation

We report a case of a 6-year-old female that initially developed polyhydramnios and short upper limbs as a fetus. In addition, the patient had multiple anomalies as a neonate, including dysmorphism, congenital heart disease, hearing loss, recurrent respiratory tract infections, skeletal abnormalities, renal cysts, and hypertension. She continues to receive multidisciplinary care, and the finding of a C.7021C > T: P.Q2341x mutation in exon 34 of the NOTCH2 gene confirms the diagnosis. To our knowledge, this is the first case to report this variant in the literature.

Discussion

Because of the rarity of this syndrome and its diverse presentation, a high index of suspicion accompanied by genetic testing is paramount for diagnosing Hajdu-Cheney syndrome. We recommend a multidisciplinary approach for these patients to provide the highest possible quality of care.

Nursing Care Plan for Patients with Hajdu-Cheney Syndrome

Hajdu-Cheney syndrome is a rare genetic disease. Its main features include phenotypic variability, age-dependent progression and the presence of acroosteolysis of the distal phalanges and generalized osteoporosis, which have significant disabling potential. Currently, there is no effective curative treatment, so nursing care is essential to ensure the maintenance of the quality of life of these patients. The main objective of this study was to establish a specific standardized nursing care plan using the NANDA-NIC-NOC taxonomy. The application of a care plan as such would improve the quality of life of patients affected by this rare disease, will contribute to increasing healthcare professionals' knowledge on this matter and will support future studies on this disease.

Hajdu-Cheney Syndrome: Report of a Case in Spain

This paper describes the case of a 54-year-old woman diagnosed with Hajdu–Cheney syndrome, who presents with characteristic craniofacial dysmorphia, short stature, premature loss of teeth, developmental skeletal disorders, fibrocystic mastopathy, bilateral hearing loss and an intermittent mild neutropenia. The patient received treatment with bisphosphonates and was awaiting evaluation for surgical arthroplasty of both hips when she suffered a motor vehicle accident, which led to a rapid progression in her disease by increasing her degree of dependence for most activities of daily living. The clinical presentation and radiologic findings seen in this case confirm the three main features of the syndrome: phenotypic variability, an age-dependent progression and the presence of generalized osteoporosis and acroosteolysis of distal phalanges. The main objective of the manuscript is to describe a new case of a patient diagnosed with Hajdu–Cheney syndrome. Due to the low prevalence of the syndrome and the small number of cases reported in the scientific literature, obtaining a complete description and a global perspective of the disease is complex.

Oral Surgery Procedures in a Patient with Hajdu-Cheney Syndrome Treated with Denosumab-A Rare Case Report

Background: Hajdu-Cheney syndrome (HCS) is a very rare autosomal-dominant congenital disease associated with mutations in the NOTCH2 gene. This disorder affects the connective tissue and is characterized by severe bone resorption. Hajdu-Cheney syndrome most frequently affects the head and feet bones (acroosteolysis). Case report: We present an extremely rare case of a 34-year-old male with Hajdu-Cheney syndrome. The patient was admitted to the Department of Oral Surgery, Medical University of Gdańsk, in order to perform the extraction of three teeth. These teeth were not eligible for conservative treatment and prosthetic reconstruction. The patient was treated with denosumab (angiogenesis and receptor activator of nuclear factor-κB RANK ligand inhibitor, RANKL). Discussion: Denosumab is a monoclonal antibody against RANKL. This drug works through a suppression of osteoclast activity. In cases of patients in which the pathway of the RANK/RANKL/osteoprotegerin is dysregulated, denosumab has been approved for the treatment off-label. In patients receiving denosumab, a delayed wound healing in the oral cavity and osteonecrosis may occur. Dental procedures involving the alveolar bone process (tooth extractions and bone alveoloplasty) may be a risk factor for medication-related osteonecrosis of the jaw (MRONJ). Spontaneous osteonecrosis is rarely observed. MRONJ consists of the destruction of exposed bone, with the exposure persisting for a minimum of 6–8 weeks. This is the first article about an HCS patient treated with denosumab who underwent invasive oral surgery procedures. This case report highlights the difficulties for professionals occurring during the oral surgery procedures in such patients.

A mutation in NOTCH2 gene first associated with Hajdu-Cheney syndrome in a Greek family: diversity in phenotype and response to treatment

INTRODUCTION

Hajdu-Cheney Syndrome (HCS) is a rare genetic autosomal dominant disorder, characterized by distinctive facial features, acroosteolysis, and severe osteoporosis. Very rarely HCS is associated with polycystic kidney disease, splenomegaly or Crohn's disease (CD). It is caused by gain-of-function mutations in NOTCH2 gene. Treatment with bisphosphonates or denosumab is reported to result in BMD increase.

OBJECTIVE

We report a mutation in exon 34 of NOTCH2 gene, in a Greek pedigree, with diverse phenotypes among members.

DESCRIPTION OF THE PEDIGREE

The 48-year-old mother had a history of a T12 vertebral fracture, postpartum at the age of 21 and two subsequent uneventful full-term pregnancies and never received treatment. Her 29-year-old son, presented with severe osteoporosis and multiple morphological vertebral fractures. Her 21-year-old daughter had recurrent vertebral fractures starting at 10 years of age. At 17 years, she developed severe CD, resistant to treatment with biologic agents, and functional hypothalamic hypogonadism. One male pedigree died of cystic fibrosis. All subjects bore the typical facial characteristics and acroosteolysis, while none had splenomegaly or renal defects. Zoledronate infusion led to BMD increase.

GENETIC TESTING

Mutation in c.6758 G > A (NM_008163.1), leading to a Trp2253Ter replacement. This mutation has been reported as possibly pathogenic (SCV000620308), but not in association with HCS.

CONCLUSIONS

Bone involvement can present with diverse severity in the same pedigree, ranging from low BMD to multiple fragility fractures. Antiresorptive therapy improves BMD, but its anti-fracture efficacy remains to be shown. The presence of CD might indicate the significant role of NOTCH2 signaling in different tissues.

Hajdu-Cheney Syndrome: A Systematic Review of the Literature

Hajdu–Cheney syndrome (HCS) is a rare genetic disease that causes acroosteolysis and generalized osteoporosis, accompanied by a series of developmental skeletal disorders and multiple clinical and radiological manifestations. It has an autosomal dominant inheritance, although there are several sporadic non-hereditary cases. The gene that has been associated with Hajdu-Cheney syndrome is NOTCH2. The described phenotype and clinical signs and symptoms are many, varied, and evolve over time. As few as 50 cases of this disease, for which there is currently no curative treatment, have been reported to date. The main objective of this systematic review was to evaluate the results obtained in research regarding Hajdu–Cheney Syndrome. The findings are reported in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines and were registered on the web PROSPERO under the registration number CRD42020164377. A bibliographic search was carried out using the online databases Orphanet, PubMed, and Scielo; articles from other open access sources were also considered. Finally, 76 articles were included, and after their analysis, we have obtained a series of hypotheses as results that will support further studies on this matter.