Atypical presentation of ACCES syndrome resembling dominant Spondyloepiphyseal dysplasia tarda

Abstract

Aplasia Cutis Congenita with Ectrodactyly Skeletal Syndrome (ACCES, OMIM #619959) is an extremely rare multiple congenital anomalies syndrome caused by haploinsufficiency of the UBA2 gene. This syndrome presents with growth retardation, dysmorphic facial features, neurodevelopmental delay, skeletal problems including ectrodactyly, developmental dysplasia of the hip (DDH) and scoliosis, skin findings such as aplasia cutis, and some internal organ abnormalities. Our 13-year-old female patient and her 38-year-old father had a skeletal dysplasia phenotype with disproportionate short stature, bilateral DDH, mild epiphyseal involvement, scoliosis, and increased lumbar lordosis. Both were neurodevelopmentally normal and had mild dysmorphic facial features and mild ectodermal findings. The dominant inheritance pattern in the pedigree suggested a pre-diagnosis of spondyloepiphyseal dysplasia tarda. The exome sequencing analysis of the patient has identified a novel heterozygous variant, NM_005499.2:c.460-2A >G, in the UBA2 gene, and the father was found heterozygous either. The isolated spondyloepiphyseal involvement of our patients was an unusual presentation compared to patients with ACCES syndrome previously reported in the literature. Considering the highly variable expressiveness of ACCES syndrome and the co-occurrence of familial hip dysplasia and vertebral problems, we suggest that this syndrome can also be classified under “Spondyloepi(meta)physial dysplasia (SE(M)D)” in the nosology of genetic skeletal disorders.