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

INTRODUCTION: Juvenile hyaline fibromatosis and infantile systemic hyalinosis are variants of the same autosomal recessive syndrome; hyaline fibromatosis syndrome, characterized by papulonodular skin lesions, gingival hypertrophy, flexion contractures of joints, osteolytic bone lesions and stunted growth. Infantile systemic hyalinosis is distinguished from juvenile hyaline fibromatosis by its more severe phenotype, which includes hyaline deposits in multiple organs, recurrent infections and death within the first two years of life. Hyaline fibromatosis syndrome is due to mutations of the gene-encoding capillary morphogenesis protein 2 (CMG2). Cases have been reported in different countries but to the best of our knowledge, this is the first reported Moroccan patient with hyaline fibromatosis syndrome and carrying the CMG2 mutation. CASE PRESENTATION: We report the case of an eight-year-old Moroccan male patient with typical features of hyaline fibromatosis syndrome: multiple recurring subcutaneous tumors, gingival hypertrophy, joint contractures and other anomalies carrying a homozygous mutation in the CMG2 gene. The identification of the mutation in our patient allowed us to do a presymptomatic diagnosis in our patient’s sister, a two-day-old newborn, who is carrying the familial mutation in the heterozygous state. Early recognition of this condition is important for genetic counseling and early treatment. CONCLUSIONS: Hyaline fibromatosis syndrome might be underdiagnosed. Molecular diagnosis will help clinicians and geneticists, firstly to conduct genetic counseling, prenatal diagnosis and early treatment, and secondly to gain better understanding of the disease and genotype-phenotype correlations.