engleski

A rare case of 8q23.3-q24.13 microdeletion in a patient with Langer-Giedion syndrome without TRPS1 gene deletion

Aim: Langer-Giedion syndrome (LGS) is a contiguous gene syndrome caused by a hemizygous deletion on chromosome 8q23.3-q24.11 involving TRPS1 and EXT1 genes. We report on a girl with a microdeletion at 8q23.3-q24.13 and clinical features of LGS. In addition to the classical LGS phenotype, the patient also has premature adrenarche. Case report: The patient is a 4-year-old girl with delayed psychomotor development and craniofacial dysmorphic features consisting of large, laterally protruding ears, bulbous nose, broad nasal bridge, elongated upper lip, thin vermilion border, and sparse scalp hair. Radiographic examination of both hands revealed delayed bone age, brachyphalangia, brachymetacarpia and cone-shaped epiphyses. Multiple cartilaginous exostoses were detected on long and short tubular bones. Her pubertal development is classified as Tanner stage 3 premature pubarche. Hormonal analysis revealed elevated DHEAS and androstendion indicating premature adrenarche. Molecular genetic analysis was performed to confirm the diagnosis of LGS. Array-comparative genomic hybridization revealed a 7.5Mb interstitial deletion at 8q23.3-q24.13 (Chr8:116.921.245bp-124.442.990bp) leaving the TRPS1 gene intact. Conclusion: Although the deletion of TRPS1 and EXT1 genes is responsible for craniofacial and skeletal features of LGS, there have been previous reports of patients with features of LGS and 8q24 deletions leaving the TRPS1 gene intact. To our knowledge, this is the third such case. These three patients have similar proximal breakpoints suggesting a functional disturbance of TRPS1 gene and deletion of potential TRPS1 regulatory sequences. Also, the combination of LGS with premature adrenarche has not yet been described, however this combination in our patient is likely by chance.

dysmorphology; microdeletion

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