Urofacial (Ochoa) syndrome with a founder pathogenic variant in the HPSE2 gene: a case report and mutation origin

Urofacial syndrome or Ochoa syndrome (UFS or UFOS) is a rare disease characterized by inverted facial expression and bladder dysfunction that was described for the first time in Colombia. It is an autosomal recessive pathology with mutations in the HPSE2 and LRIG2 genes. However, 16% of patients do not have any mutations associated with the syndrome. Despite the importance of neurobiology in its pathophysiology, there are no neurological, neuropsychological, or psychological studies in these patients. A 30-year-old male from Medellín, Colombia, with a significant perinatal history, was diagnosed with grade 4 hydronephrosis on his first ultrasound test. At 4 months of age, symptoms such as hypomimia, lagophthalmos, and recurrent urinary tract infections started to manifest. Imaging studies revealed urinary tract dilatation, vesicoureteral reflux, and a double collector system on his left side, which led to the diagnosis of UFS. Multiple procedures, including vesicostomy, ureterostomy, and enterocystoplasty, were performed. At 20 years of age, he achieved urinary sphincter control. Genetic analysis revealed a founder pathogenic variant, c.1516C > T (p.Arg506Ter), in the HPSE2 gene, which produces a truncated protein that lacks 86 amino acids. This variant is classified as pathogenic according to the ClinVar database for UFS. The mutation age is approximately 260-360 years, and the two alleles share a 7.2-7.4 Mb IBD segment. Moreover, we detected European local ancestry in the IBD segment, which is consistent with a Spanish introduction. Neurological examination, neuropsychological assessment, and psychological testing revealed no abnormalities, except for high stress levels. Clinical analysis of this patient revealed distorted facial expression and detrusor-sphincter dyssynergia, which are typical of patients with UFS. Genetic analysis revealed a pathogenic variant in the HPSE2 gene of European origin and a mutation age of 260-360 years. From a neurological, neuropsychological, and psychological (emotional and personality) perspective, the patient showed no signs or symptoms of clinical interest.