ESPE Abstracts

Introduction: Brachydactyly is defined as shortening of metatarsal and metacarpal bones. There are different types of brachydactyly which can be isolated or associated with syndromes. The underlying gene defect has been identified in the majority of isolated brachydactylic and some syndromic forms. We herein report a Saudi male patient who presented with brachydactyly and short stature and found to have a rare form of skeletal dysplasia related to PTHLH gene mutation which is never reported before nationally.

Case report: 13 years old, Saudi boy, product of uneventful pregnancy of non-consanguineous parents visited the endocrine clinic with concerning of the shortening of the fingers and toes on both sides. There is no family history of similar condition or skeletal dysplasia and he is developmentally well. Upon physical examination, He is noticed to have short stature while other growth parameters were normal. No dysmorphic features were noticed. His skin examination revealed no nodules or skin changes and kyphoscoliosis was not detected. Thyroid exam revealed no goiter or other abnormalities. His nails examination and dental assessment were normal with no chest deformities. Musculoskeletal evaluation revealed broad hands and feet with brachydactyly. He is vitally stable and other systemic examinations were unremarkable. Parents’ assessment reveled normal height with no brachydactyly. The breast development of the patient mother was normal and there was no issue with breast feeding. His labs including bone profile was normal. Hormonal workups showed normal PTH level and thyroid function test. Urinary studies showed normal urinary calcium and creatinine level. Skeletal survey was performed which revealed bilateral nearly symmetric metacarpals and metatarsals with lesser degree phalangeal shortening and broadening of both hands and feet. Spine radiograph was normal with advancement in his bone age.

Discussion: His clinical picture suggestive of skeletal dysplasia with no hormone resistance, genetic team was involved and whole exome sequencing reveled a deletion in the PTHLH gene on chromosome 12 which is autosomal dominant disorder characterized by short stature and brachydactyly. Parents genetic testing was negative.

Conclusion: Give the rarity of brachydactyly and such mutation, it is crucial to procced with complete physical assessment taking into consideration the whole family assessment and incomplete penetrance of such mutation. According to physical evaluation beside hormonal workups and radiological imaging, genetic testing should be considered if the results might affect patient care or family counselling.