PhotoQuiz 69

This 7-year-old male child, born to nonconsanguineous parents, presented with altered behavior and visual deficits noted over the past 6 months. Magnetic resonance imaging of the brain showed typical findings [T2 and fluid attenuated inversion recovery (FLAIR) axial images are provided]. Identify the condition and the metabolic assay to be done for confirmation of the diagnosis.Answer to PhotoQuiz 68 Short-rib thoracic dysplasia (SRTD) with or without polydactyly SRTD with or without polydactyly refers to a group of autosomal recessive skeletal ciliopathies that are characterized by a short narrow thorax, short ribs, shortened tubular bones, and a 'trident' appearance of the acetabular roof. Some of the disorders in this group were previously labelled as Jeune syndrome or asphyxiating thoracic dystrophy (ATD) or short rib-polydactyly syndrome (SRPS). Ellis-van Creveld syndrome is also included in this group. Some of the cases are lethal during neonatal period due to severe constricted thoracic cage while some survive. Pulmonary infection can compromise health. At least 23 causative genes are known and some of the genes are yet to be identified. This patient had a homozygous variant in the TTC21B gene. The various disorders in this group have overlapping features and major non-skeletal anomalies may be present. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.