Gómez-López-Hernández syndrome in a Japanese patient: a case report

Nanopore long-read sequencing analysis reveals ZIC1 dysregulation caused by a de novo 3q inversion with a breakpoint located 7 kb downstream of ZIC1

Zic family member 1 (ZIC1), a gene located on chromosome 3q24, encodes a transcription factor with zinc finger domains that is essential for the normal development of the cerebellum. Heterozygous loss-of-function of ZIC1 causes Dandy-Walker malformation, while heterozygous gain-of-function leads to a multiple congenital anomaly syndrome characterized by craniosynostosis, brain abnormalities, facial features, and learning disability. In this study, we present the results of genetic analysis of a male patient with clinically suspected Gomez-Lopez-Hernandez syndrome. The patient displayed multiple congenital abnormalities, including bicoronal craniosynostosis, characteristic facial features, cerebellar malformation with rhombencephalosynapsis, and temporal alopecia, and a de novo inversion of chromosome 3q. Breakpoint analysis using a Nanopore long-read sequencer revealed a breakpoint in the distal centromere of 3q24 located 7 kb downstream of the 3' untranslated region of ZIC1. On the basis of the clinical similarities, we concluded that the abnormalities in this patient were caused by the transcriptional dysregulation of ZIC1. We hypothesize the underlying molecular mechanisms of transcriptional dysregulation of ZIC1 such as the abnormalities in topologically associated domains encompassing ZIC1. This study highlights the usefulness of long-read sequencing in the analysis of de novo balanced chromosomal abnormalities.

Neuroimaging Findings in Pediatric Genetic Skeletal Disorders: A Review

Genetic skeletal disorders (GSDs) are a heterogeneous group characterized by an intrinsic abnormality in growth and (re-)modeling of cartilage and bone. A large subgroup of GSDs has additional involvement of other structures/organs beside the skeleton, such as the central nervous system (CNS). CNS abnormalities have an important role in long-term prognosis of children with GSDs and should consequently not be missed. Sensitive and specific identification of CNS lesions while evaluating a child with a GSD requires a detailed knowledge of the possible associated CNS abnormalities. Here, we provide a pattern-recognition approach for neuroimaging findings in GSDs guided by the obvious skeletal manifestations of GSD. In particular, we summarize which CNS findings should be ruled out with each GSD. The diseases (n = 180) are classified based on the skeletal involvement (1. abnormal metaphysis or epiphysis, 2. abnormal size/number of bones, 3. abnormal shape of bones and joints, and 4. abnormal dynamic or structural changes). For each disease, skeletal involvement was defined in accordance with Online Mendelian Inheritance in Man. Morphological CNS involvement has been described based on extensive literature search. Selected examples will be shown based on prevalence of the diseases and significance of the CNS involvement. CNS involvement is common in GSDs. A wide spectrum of morphological abnormalities is associated with GSDs. Early diagnosis of CNS involvement is important in the management of children with GSDs. This pattern-recognition approach aims to assist and guide physicians in the diagnostic work-up of CNS involvement in children with GSDs and their management.