Hyaline fibromatosis syndrome with mutation c.1074delT of the CMG2 gene: a case report

Hyaline Fibromatosis Syndrome Diagnosed by Whole Genome Sequencing

Hyaline fibromatosis syndrome is an extremely rare autosomal recessive condition caused by biallelic pathogenic variants in the ANTXR2 gene that leads to abnormal growth of hyalinized fibrous tissue. Severity ranges from life-threatening intractable diarrhea, recurrent infection, and acute pain to milder disease resulting in skin lesions and less severe contractures. Here, we report the case of a 3-month-old female who presented with joint contractures and severe pain followed by failure to thrive. Diagnosis via ultra-rapid whole genome sequencing allowed our team to provide appropriate care and anticipatory guidance for this patient and family.

Multisystemic Manifestations of Hyaline Fibromatosis Syndrome: Implications for Diagnosis and Management

Hyaline fibromatosis syndrome (HFS) is a rare autosomal recessive disorder characterized by the deposition of hyaline material in the skin, soft tissues, and bones. In this report, we discuss a case of a six-month-old male with HFS who presented with faltering growth, chronic diarrhea, multiple joint contractures, joint stiffness, hyperpigmented skin over bony prominences, gingival hypertrophy, patent foramen ovale, and symmetric periventricular hyperintensities on brain MRI. The diagnosis of HFS was confirmed by skin biopsy and genetic testing, which identified a homozygous mutation in the anthrax toxin receptor 2 (ANTXR2) gene. The patient was managed symptomatically with nutritional support, physiotherapy, analgesics, and regular dental care. He also received intralesional corticosteroid therapy, which significantly decreased the size of the skin nodules. His hyperpigmented skin and gingival hypertrophy remained stable, and the patent foramen ovale was managed conservatively. This case report highlights the importance of early diagnosis and management of HFS and the benefits of involving a multidisciplinary team to improve the quality of life of affected individuals.

Hyaline fibromatosis syndrome: Clinical update and phenotype-genotype correlations

Hyaline fibromatosis syndrome (HFS) is the unifying term for infantile systemic hyalinosis and juvenile hyaline fibromatosis. HFS is a rare autosomal recessive disorder of the connective tissue caused by mutations in the gene for anthrax toxin receptor-2 (ANTXR2). It is characterized by abnormal growth of hyalinized fibrous tissue with cutaneous, mucosal, osteoarticular, and systemic involvement. We reviewed the 84 published cases and their molecular findings, aiming to gain insight into the clinical features, prognostic factors, and phenotype-genotype correlations. Extreme pain at minimal handling in a newborn is the presentation pattern most frequently seen in grade 4 patients (life-limiting disease). Gingival hypertrophy and subcutaneous nodules are some of the disease hallmarks. Though painful joint stiffness and contractures are almost universal, weakness and hypotonia may also be present. Causes of death are intractable diarrhea, recurrent infections, and organ failure. Median age of death of grade 4 cases is 15.0 months (p25-p75: 9.5-24.0). This review provides evidence to reinforce the previous hypothesis that missense mutations in exons 1-12 and mutations leading to a premature stop codon lead to the severe form of the disease, while missense pathogenic variants in exons 13-17 lead to the mild form of the disease. Multidisciplinary team approach is recommended.

Two novel mutations in the ANTXR2 gene in a Chinese patient suffering from hyaline fibromatosis syndrome: A case report

Hyaline fibromatosis syndrome (HFS; MIM 228600) is a rare autosomal recessive disorder characterized by the abnormal growth of hyalinized fibrous tissue at subcutaneous regions on the scalp, ears and neck. The disease is caused by either a homozygous or compound heterozygous mutation of the anthrax toxin receptor 2 (ANTXR2) gene. The present study describes a patient with HFS confirmed by clinical examination as well as histopathological and genetic analyses. Numerous painless and variable‑sized subcutaneous nodules were observed on the scalp, ear, trunk and four extremities of the patient. With increasing age, the number and size of the nodules gradually increased in the patient. The patient additionally presented with severe gingival thickening and developed pearly papules on the ears, back and penis foreskin. Biopsies of ear nodules revealed that the tumor was located in the dermis, and no marked alterations were observed in the epidermis compared with healthy patients. Spindle‑shaped or round tumor cells were revealed to be immersed in the eosinophilic hyaline ground substance. Furthermore, a skeletal X‑ray of the patient revealed multiple low‑density imaging on the right distal humerus. Compound heterozygous mutations in the ANTXR2 gene were identified in the patient: c.470_472del in exon 5 and c.1073 delC in exon 13. c.470_472del were revealed to be inherited from his mother and father, respectively. These two mutations, c.470_472del and c.1073 delC, to the best of our knowledge, have not previously been identified. Identification of the mutations in ANTXR2 may make prenatal diagnosis of HFS possible during future pregnancies.

Protein-losing enteropathy and joint contractures caused by a novel homozygous ANTXR2 mutation

Infantile systemic hyalinosis (ISH) is a rare autosomal recessive disorder and an allelic form of hyaline fibromatosis syndrome that is caused by mutations in the ANTRX2 gene encoding the transmembrane anthrax toxin receptor 2. Its main features include characteristic skin lesions, joint contractures, persistent diarrhea, and failure to thrive due to accumulation of hyaline material in multiple organs. The resulting severe malnutrition can cause death in early infancy. Because of its rarity and high fatality rate, timely diagnosis is difficult and ISH may be underdiagnosed. In this report, we describe a 10-month-old male with severe protein-losing enteropathy, skin lesions, and painful joint contractures, diagnosed with ISH based on skin his-topathology and identification of a novel homozygous ANTRX2 mutation, c.1127_1128delTG (p.V376Gfs*14). While its clinical outcome is poor without curative treatment, establishing a diagnosis of ISH starting from clinical suspicion to molecular analysis is important for appropriate medical management and for risk and carrier assessment of family members.

Diagnosis implications of the whole genome sequencing in a large Lebanese family with hyaline fibromatosis syndrome

BACKGROUND

Hyaline fibromatosis syndrome (HFS) is a recently introduced alternative term for two disorders that were previously known as juvenile hyaline fibromatosis (JHF) and infantile systemic hyalinosis (ISH). These two variants are secondary to mutations in the anthrax toxin receptor 2 gene (ANTXR2) located on chromosome 4q21. The main clinical features of both entities include papular and/or nodular skin lesions, gingival hyperplasia, joint contractures and osteolytic bone lesions that appear in the first few years of life, and the syndrome typically progresses with the appearance of new lesions.

METHODS

We describe five Lebanese patients from one family, aged between 28 and 58 years, and presenting with nodular and papular skin lesions, gingival hyperplasia, joint contractures and bone lesions. Because of the particular clinical features and the absence of a clinical diagnosis, Whole Genome Sequencing (WGS) was carried out on DNA samples from the proband and his parents.

RESULTS

A mutation in ANTXR2 (p. Gly116Val) that yielded a diagnosis of HFS was noted.

CONCLUSIONS

The main goal of this paper is to add to the knowledge related to the clinical and radiographic aspects of HFS in adulthood and to show the importance of Next-Generation Sequencing (NGS) techniques in resolving such puzzling cases.

Hyaline Fibromatosis Syndrome: A Rare Inherited Disorder

Hyaline fibromatosis syndrome (HFS) is rare autosomal recessive disease characterized by the deposition of amorphous hyaline material in skin and visceral organs. It represents a disease spectrum with infantile systemic hyalinosis (ISH) being the severe form and juvenile hyaline fibromatosis (JHF) being the mild form. Dermatologic manifestations include thickened skin, perianal nodules, and facial papules, gingival hyperplasia, large subcutaneous tumors on the scalp, hyperpigmented plaques over the metacarpophalangeal joints and malleoli, and joint contractures. ISH shows a severe visceral involvement, recurrent infections, and early death. We report a case of 2.5-year-old female patient who presented with HFS who had overlapping features of both ISH and JHF. To the best of our knowledge, very few cases of HFS have been reported in Indian literature till date.

Infantile systemic hyalinosis: Report of two severe cases from Saudi Arabia and review of the literature

Infantile systemic hyalinosis (ISH) (OMIM 228600) is a rare fatal autosomal recessive disorder characterized by extensive deposition of hyaline material in many tissues. Consanguinity has been recorded in many cases. Herein we present two new Saudi cases with review of the literature. Our first proband was a 9 month-old male who was the first baby for parents descended from a closed consanguineous pedigree. The second proband was a 13 month-old male who was the first baby for consanguineous parents (3(rd) C). Both cases presented with bilateral painful limited limb movement with joints contractures, low birth weight (< P5), severe generalized stiff skin, hyper-pigmented skin over bony prominences, fleshy perianal masses and gingival hypertrophy. The first child died at 18(th) month as a result of recurrent chest infections. The second proband showed a severe progressive course of joint contractures, and died at 19(th) month because of failure to thrive and recurrent infections. Although the clinical features of ISH are characteristic, the disease is under/miss diagnosed. The role of consanguinity needed to be highlighted to the community. Careful clinical examination and molecular diagnosis will be helpful for genetic counseling, prenatal diagnosis and early treatment.