Dental agenesis in Kallmann syndrome individuals with FGFR1 mutations

International Journal of Paediatric Dentistry 2010; 20: 305–312 Background. Kallmann syndrome (KS) is a rare genetic disorder characterised by central hypogonadism with a lack of sense of smell and in some cases renal aplasia, deafness, syndactyly, cleft lip/palate, and dental agenesis. To date, five genes for KS have been identified: KAL1, located on the X chromosome, and FGFR1, PROKR2, PROK2 and FGF8, which are involved in autosomally transmitted forms of KS. Aim. The study characterised the dental ageneses of individuals with KS associated with mutations in the FGFR1 gene. Design. Six individuals displaying dental agenesis were included. Clinical and radiological dental evaluations as well as medical anamneses were carried out. Results. Microdontia, screwdriver‐shaped mandibular incisors, thin molar roots, and patterns of dental agenesis in both dentitions were observed. One to nine teeth were missing, most frequently, in descending order, lateral mandibular incisors, second premolars of upper and lower jaws, and lateral maxillary incisors. The pattern of dental agenesis is associated with four new mutations in the FGFR1 gene. Conclusion: Dental agenesis may be a clinical feature of Kallmann syndrome caused by a mutation in the FGFR1 gene. These findings highlight the role that odontologists can play in the early diagnosis and treatment of gonadotropic deficiency.