Aminoacyl-tRNA synthetases play a pivotal role in catalyzing the precise coupling of amino acids with their corresponding tRNAs. Among them, Tyrosyl tRNA synthetase, encoded by the YARS1 gene, facilitates the aminoacylation of tyrosine to its designated tRNA. Heterozygous variants in the YARS1 gene have been linked to autosomal dominant Charcot-Marie-Tooth type C, while recent findings have unveiled biallelic YARS1 variants leading to an autosomal recessive multisystemic disorder in several cases. In this report, we present a novel case characterized by dysmorphic facies, and multisystemic symptoms, prominently encompassing neurological issues and a microarray conducted shortly after birth revealed 47, XXY. Utilizing whole exome sequencing, we uncovered a paternally inherited likely pathogenic variant (c.1099C > T, p.Arg367Trp), previously reported, coinciding with the father\'s history of hearing loss and neurological symptoms. Additionally, a maternally inherited variant of uncertain significance (c.782T > G, p.Leu261Arg), previously unreported, was identified within the YARS1 gene. The observed phenotypes and the presence of compound heterozygous results align with the diagnosis of an autosomal recessive disorder associated with YARS1. Through our cases, the boundaries of this emerging clinical entity are broadened. This instance underscores the significance of comprehensive genetic testing in patients exhibiting intricate phenotypes.

Triple X syndrome (47,XXX) is a numerical chromosomal alteration that affects 1/1,000 women, in which the woman is born with an extra X chromosome. Some oral changes have been reported in the literature, as hypodontia, influence on deposition of crown enamel and discrepancies in cephalometric measurements. Other systemic complications may lead to oral abnormalities similar to those seen in triple X patients, such as congenital hypothyroidism (CH). This paper reports a triple X syndrome case associated with CH later treated. Besides delay in cognitive and intellectual development, the patient had changes in teeth development and in cephalometric measurements with deficiencies in the maxilla and mandible. This is the first report of a triple X syndrome associated with CH. Both conditions may result in changes in dentofacial development.