(482.4) Facial dysmorphologies in genetic disorders: exploring the ancestry component in a Colombian population

Poster Board Number: C119
Introduction: AAA has separate poster presentation times for odd and even posters.
Odd poster #s – 10:15 am – 11:15 am
Even poster #s – 11:15 am – 12:15 pm

Neus Martínez Abadías (GREAB-Research Group in Biological Anthropology. Department of Evolutionary Biology, Ecology and Environmental Sciences, BEECA. Universitat de Barcelona), Luis Miguel Echeverry (GREAB-Research Group in Biological Anthropology. Department of Evolutionary Biology, Ecology and Environmental Sciences, BEECA. Universitat de Barcelona, GREAB-Research Group in Biological Anthropology. Department of Evolutionary Biology, Ecology and Environmental Sciences, BEECA. Universitat de Barcelona), Eidith Gómez (CIACER-Centro de Investigaciones en Anomalías Congénitas y Enfermedades Raras, Universidad Icesi), Paula Solís (CIACER-Centro de Investigaciones en Anomalías Congénitas y Enfermedades Raras, Universidad Icesi), Estephania Candelo (CIACER-Centro de Investigaciones en Anomalías Congénitas y Enfermedades Raras, Universidad Icesi), Diana Ramírez-Montaño (CIACER-Centro de Investigaciones en Anomalías Congénitas y Enfermedades Raras, Universidad Icesi), Diana Ortiz (CIACER-Centro de Investigaciones en Anomalías Congénitas y Enfermedades Raras, Universidad Icesi), Alejandro González (GTM–Grup de Recerca en Tecnologies Mèdia, La Salle, Universitat Ramon Llull), Xavier Sevillano (GTM–Grup de Recerca en Tecnologies Mèdia, La Salle, Universitat Ramon Llull,), Juan Carlos Cuéllar (Universidad Icesi), Harry Pachajoa (CIACER-Centro de Investigaciones en Anomalías Congénitas y Enfermedades Raras, Universidad Icesi, CIACER-Centro de Investigaciones en Anomalías Congénitas y Enfermedades Raras, Universidad Icesi)

Currently there are more than 10,000 rare diseases that affect about 7% of the worlds population. Up to 40% of rare genetic disorders present craniofacial dysmorphologies, which can vary from subtle facial anomalies to severe malformations. Visual assessment of facial dysmorphology is commonly used for clinical diagnosis, patient management and treatment monitoring. However, qualitative descriptions are usually vague and quantitative approaches using craniofacial phenotypes for the diagnosis of rare diseases are based on North American and European populations, disregarding the influence of population ancestry on facial variation, as in Latin-America. In this study, we assessed facial dysmorphologies associated to three different genetic disorders (Down (DS), Morquio (MS) and Noonan syndrome (NS)) in a Latin-American population from Cali (Colombia). We recorded the coordinates of 18 facial landmarks in 2D images from 34 pediatric patients (19 DS, 8 MS, 6 NS) and 75 controls and quantified facial differences between patients and control groups using Euclidean Distance Matrix Analysis (EDMA).

Comparisons between control and syndromic phenotypes indicated that individuals diagnosed with DS and MS presented the largest percentage of dysmorphologies, with respectively 56.2% and 54.9% of significantly different facial traits. In NS, the percentage decreased to 12.4%. Each syndrome presented a characteristic facial pattern. In DS, all facial structures were affected, with a 6% increase of relative distance between the eyes and a 7-10% reduction in facial height. The eyes and nose were most affected in MS, but not the mouth, with higher hypertelorism and facial reduction than in DS (9% and 8-17%). In NS, facial differences were more subtle and affected mainly the eyes and mouth, reducing the relative distance between them from 1 to 4% in patients as compared to controls. Our study provides a precise quantitative comparison of facial dysmorphologies in three genetic disorders that in the future can be compared with other world-wide populations to test whether facial traits associated to disease are altered by different evolutionary and adaptive histories of human populations.

Proyecto COL0012168-1097 Interfacultades-ICESI, and 2017SGR1630. Research group (AGAUR).