Frontometaphyseal dysplasia (FMD) is a dominant X-linked rare disease caused by mutations of FLNA. The distinctive features of FMD include skeletal dysplasia, facial dysmorphism, extremities anomalies, deafness, cleft palate and eye anterior segment anomalies, yet none of the complications, such as acro-osteolysis, keratitis, xerosis or poikiloderma, have been reported in FMD.Patient concerns:
A 29-year-old mother and her 7-year-old daughter, both presented with congenital glaucoma, craniofacial dysmorphism, xerosis and poikiloderma, were admitted to our hospital in 2011. Additionally, the mother also suffered from acro-osteolysis, keratitis, camptodactyly of hands and metastatic cutaneous squamous cell carcinoma (SCC) which turned out to be fatal 5 years later. In 2017, keratitis and acro-osteolysis were noticed in the daughter as well. Radiography showed bowed long bones with thickening cortex, and distal phalangeal osteolysis.Diagnoses:
Whole genome sequencing (WGS) was conducted in 2016, resulting in 71491 single-nucleotide polymorphisms and 7616 indels shared by patients while the father was taken as control. A FLNA variant was classified likely pathogenic, supporting the diagnoses of FMD. In addition, though our patients’ symptoms were highly consistent with xeroderma pigmentosum variant, a mild subtype of xeroderma pigmentosum (XP) with merely accumulated UV-induced lesions like xerosis and poikiloderma limited to sun-exposure sites, higher risks of cutaneous neoplasms and absence of classical XP features, WGS didn’t find supportive genetical evidence, but 2 HERC2 variants were assigned highest suspicion in both XP and SCC by bioinformatical analyses.Interventions:
Anti-inflammatory treatment, sunscreens and moisturizers were administered.Outcomes:
The daughter's cutaneous lesions developed slowly during the 6-year follow-up, but the keratitis seriously weakened her sight.Lessons:
To our knowledge, it's the first report of cases carrying FMD, keratitis, xerosis, poikiloderma and acro-osteolysis simultaneously, and 3 likely pathogenic variants were identified. Whole genome/exon sequencing is recommended as a common test for patients with rare phenotypes.