Focal dermal hypoplasia in a male neonate: a case report and literature review / 中华围产医学杂志

ABSTRACT

Objective To investigate the clinical and genetic characteristics of focal dermal hypoplasia (FDH) in children. Methods Clinical data, relevant examinations, histopathological features and genetic test results of a male newborn with FDH who was admitted to the neonatal ward of Beijing Children's Hospital of Capital Medical University were retrospectively analyzed. Reports of pediatric FDH patients with complete clinical data were retrieved from PubMed, Wanfang database and China National Knowledge Infrastructure from the establishment of these databases to March 2018 and characteristics of FDH was summarized. Results The case we reported here was a male neonate diagnosed with FDH in China, who was born with microcephaly, bilateral auricular cartilage dysplasia, tooth germ dysplasia and bipedal deformity and his skin, bone, gingiva, bilateral iris and pupils were all involved. Histopathological examination of the skin suggested dermal dysplasia. Genetic analysis showed a suspected chimeric nucleotide variation in PORCN gene (c.268 C>T), whereas no abnormalities were found in his parents and sister. A total of 60 cases (including the one we reported) of FDH diagnosed in childhood were reviewed, and 19 of them were confirmed in neonatal period. Fifty-seven of the 60 cases (95.0%) developed typical skin dysplasia and 56 cases (93.3%) with skeletal malformations, while other clinical manifestations vary. Histopathological examination suggested as dermis dysplasia, adipose tissue migration and reduction of appendage and collagen fibers. Among the 60 children, 19 (including four onset at neonatal period) underwent genetic testing and the results indicated PORCN gene mutation. Mutations in the four with neonatal-onset were c.956dupA, c.1061T>C, c.749C>T and c.268C>T. As the reported case was a boy, with only one X chromosome, the PORCN gene mutation could directly affected its function resulting in the abnormal phenotype. It was a de novo mutation as the same mutation was not detected in his parents. Conclusions FDH is a hereditary disease involving multiple systems with various clinical manifestations. Skin histopathological examination and genetic testing should be performed as soon as possible for early diagnosis and intervention. Accurate diagnosis is essential for genetic counseling, reproductive planning, prospective guidance and prognosis.