Olfactory bulb hypoplasia and congenital anosmia in PTCH1-related Gorlin-Goltz syndrome: An emerging association.

INTRODUCTION

Congenital anosmia (CA) is a rare developmental condition that may occur in isolation or as part of a syndromic disorder. Gorlin-Goltz syndrome (GGS), an autosomal dominant condition most commonly caused by pathogenic variants in PTCH1, is classically characterized by cutaneous, odontogenic and skeletal abnormalities, while neurological manifestations remain incompletely defined.

CASE SUMMARY: We report the case of a 10-year-old girl with genetically confirmed PTCH1-related GGS who presented with lifelong anosmia. Otolaryngological evaluation confirmed absent olfactory function by psychophysical testing and electrophysiological assessment. Neuroimaging revealed bilateral olfactory bulb hypoplasia. Endocrinological evaluation excluded hypogonadotropic hypogonadism, distinguishing this phenotype from classical Kallmann syndrome.

DISCUSSION: This case adds to the limited, but growing evidence supporting an association between CA and PTCH1-related GGS, highlighting the role of disrupted Sonic Hedgehog signaling in olfactory system development. Recognition of olfactory dysfunction in these patients may contribute to a broader understanding of the neurodevelopmental spectrum associated with PTCH1 mutations.