Phenotypic presentations of Hajdu-Cheney syndrome according to age - 5 distinct clinical presentations

Exploratory use of romosozumab for osteoporosis in a patient with Hajdu-Cheney syndrome: a case report

Hajdu-Cheney syndrome (HCS) is an inherited skeletal disorder caused by mutations in the Notch homolog protein 2 gene (NOTCH2). Treatment of this rare disease is challenging because there are no established guidelines worldwide. Previous case reports using bisphosphonates, denosumab, or teriparatide suggested that curative treatment for HCS did not exist yet in terms of preventing the disease progression. Therefore, the efficacy of romosozumab for osteoporosis in patients with HCS needs to be evaluated. Herein, we report the case of a 43-year-old woman who had progressive acro-osteolysis and repeated fractures since the age of 29 years. Next-generation sequencing confirmed HCS with a mutation at nucleotide 6758G>A, leading to Trp2253Ter replacement in NOTCH2. Romosozumab treatment was initiated because she had already received bisphosphonate for more than 10 years at other hospitals. After 1 year of romosozumab treatment, the bone mineral density (BMD) increased by 10.2%, 6.3%, and 1.3%, with Z scores of -2.9, -1.6, and -1.2 at the lumbar spine, femoral neck, and total hip, respectively. In addition, C-telopeptide was suppressed by 26.4% (0.121 to 0.089 ng/mL), and procollagen type I N-terminal propeptide increased by 18.7% (25.2 to 29.9 ng/mL). This was the first report of romosozumab treatment in patient with osteoporosis and HCS in Korea. One year of romosozumab treatment provided substantial gains in BMD with maintaining the last acro-osteolytic status without deteriorating, representing a possible treatment option for HCS.

Hajdu-Cheney Syndrome: A Novel NOTCH2 Mutation in a Spanish Child in Treatment with Vibrotherapy: A Case Report

A case report of an 11-year-old boy with a de novo variant in NOTCH2 and clinical features characteristic of Hajdu-Cheney syndrome is reported, with acroosteolysis of the distal phalanges of the feet and hands, generalized osteoporosis, musculoskeletal and craniofacial alterations, short stature, bowing of long bones, vertebral anomalies, genu recurvatum, hypertrichosis, joint and skin hyperlaxity, atopic dermatitis, megalocorneas, micrognathia and frequent respiratory infections, among others. Treatment is with bisphosphonates in the framework of bone density improvement and with focal vibration therapy for rehabilitation of the musculoskeletal system and gait improvement. The three generalities of this pathology-phenotypic variability, degenerative character and the presence of generalized osteoporosis and acroosteolysis of the distal phalanges-are seen in this case, whose diagnostic confirmation was made by genetic study.

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.

Hajdu Cheney syndrome; A novel NOTCH2 mutation in a Syrian child, and treatment with zolidronic acid: A case report and a literature review of treatments

INTRODUCTION

Hajdu Cheney Syndrome (HCS) is a rare genetic disorder characterized by skeletal deformities such as acroosteolysis, osteoporosis, unique craniofacial features, and other systemic abnormalities. This syndrome is caused by NOTCH2 gene mutations, which cause an increase of osteoclast and osteoblast activity that leads to the increased bone resorption. Because of how rare the syndrome is and the vague onset of the symptoms, it can be challenging to make an early diagnosis.

CASE PRESENTATION

We report a case of a female child with HCS who has a new NOTCH2 mutation sequence; (NM_024408.3:c.6463G > T) protein change (Glu2155*), and to our knowledge this is the first reported and diagnosed case in Syria. She presents with short stature, unique craniofacial features, scoliosis, kyphosis, and signs of osteoporosis, in addition to Patent Ductus Arteriosus. The patient was diagnosed with Hajdu Cheney Syndrome, and administered zolidronic acid, and she responded well to the treatment; showing signs of improved bone density and improvement in height, where her bone density improved from 0.23 to 0.31, and she gained 11 cm in height after the treatment.

CONCLUSION

Due to the rarity of the syndrome, there is no established guideline for treatment yet. Based on the pathophysiology of the syndrome that causes increased bone resorption, treatment with the Bisphosphonates group has yielded positive outcomes. Furthermore, we compare different treatments in the literature with their results.

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.