Craniofacial patterning in Klinefelter (47 XXY) adults

Area of Science:

• Medical Genetics
• Anthropology
• Orthodontics

Background:

• Klinefelter syndrome (47,XXY) is a common genetic condition affecting males.
• Craniofacial morphology can be influenced by genetic and developmental factors.
• Previous studies have suggested potential craniofacial differences in individuals with Klinefelter syndrome.

Purpose of the Study:

• To compare the craniofacial morphology of adult males with Klinefelter syndrome (47,XXY) to their first-degree relatives.
• To identify specific cephalometric differences in craniofacial linear dimensions and facial shape.
• To investigate potential influences of the 47,XXY karyotype on cranial base and jaw growth.

Main Methods:

• Radiographic cephalometry was employed for quantitative analysis.
• Pattern profile analysis was utilized to assess facial shape and dimensions.
• A cohort of 26 adult Klinefelter males was compared with 15 male and 14 female first-degree relatives.

Main Results:

• Klinefelter males (47,XXY) showed significantly larger craniofacial linear dimensions compared to female relatives.
• Mandibular dimensions differed notably between Klinefelter males and unaffected relatives, with larger corpus length, shorter ramus, and more obtuse gonial angle in the 47,XXY group.
• Klinefelter subjects displayed a more acute median cranial base angle and greater variability in craniofacial structures.

Conclusions:

• The 47,XXY karyotype is associated with specific craniofacial morphological differences, particularly in mandibular structure and facial profile.
• Greater variability in craniofacial patterns among Klinefelter males may indicate decreased developmental canalization.
• The 47,XXY condition potentially impacts endochondral growth in the cranial base and direct jaw development.