Proximal Microdelection 16p11.2 Syndrome

Clinical History and Symptoms: XX, 9.37 years, was referred to our Clinic for obesity and psycho-motor delay. Family history: Fibromyalgic mother, two maternal cousins with psycho-motor delay, paternal uncle with epilepsy and intellectual disability. Born at term from caesarean section for placental detachment after physiological pregnancy (birth weight g 1900, SGA). In the first years of life she had psychomotor retardation, episodes of affective spasms, nocturnal enuresis, aggression in case of food containment, allergic asthma in steroid therapy, DSA and language disorder (followed by territorial NPI and scholastic support), headache (negative brain MRI, no EEG anomalies, on therapy with Oxcarbazepina), mild right transmission hearing loss. XX was previously submitted to several investigations: Rx rachis (left-convex scoliotic attitude, bilateral cervical rib sketch, antiversion of the physiological lordosis), echocardiography (normal), basic hormonal blood-based were substantially normal. At physical exam height and BMI were at the upper percentiles (83° perc, SDS 0.95, TH-SDS 2.13 and 29.7 kg / m2, respectively). She showed initial signs of pubertal activation (P1-2, S2, A +/-) and several dysmorphic features: synophry, reduced intercantal distance, small mouth, acanthosis at the base of the neck, hump, lower limb valgus, fifth finger clinodactyly of right hand, relevant abdominal adipose panniculus. Diagnostic Hypothesis and I and Ii Level Investigations: We measured TSH (2,49 mcUI/ml) and FT4 (13,9 pg/ml), cortisolemia at the lower limits (2,3 mcg/dl) with normal adrenal function, prepubertal hormonal structure and initial insulin resistance (blood sugar / insulin 4.06, HOMA index 4.10); abdomen ultrasound (steatosis); fibroscan (modest fibrosis); karyotype (normal female). Diagnosis and Eventual Therapy: On the basis of dysmorphic signs microarray analysis was performed that detect a deletion of approximately 813kb in 16p11.2 arr [hg19] 16p11.2 (29.427.215-30.240.227) x1, including the deletion of 593kb responsible for Proximal Microdelection 16p11.2 syndrome. This syndrome, from contiguous genes, is characterized by delayed development and language, mild cognitive impairment, social disability (autism spectrum disorders), mild variable dysmorphism, EEG abnormalities, predisposition to obesity, vertebral anomalies. Microdeletion 16p11.2 (Group 1) explains all the clinical features presented by our patient. The presence of obesity, in absence of involvement of the gene recognized as causative of the same, suggests that the deletion in question affects a gene region involved in the predisposition to obesity, not yet described in the literature.