Inclusion Criteria:  Male or female child Aged from 1 month to 3 months and a half Placement of a prosthesis in a patient with isolated upper limb deficiency, type of congenital transverse unilateral amputation of the forearm segment Socially insured patient, Patient willing to comply with all study procedures and study duration Written informed consent from patient's legal guardians  Exclusion Criteria:  Children with one or more high risk factors for neurodevelopmental disorders:  Very prematurity (<32 weeks of amenorrhea [SA]) Premature infants <37 WA with intrauterine growth retardation (IUGR) or low weight for gestational age (PAG) <3rd percentile or <- 2 SD for GA and sex according to national reference curves) A presumed hypoxo-ischemic encephalopathy with an indication of therapeutic hypothermia A perinatal arterial cerebrovascular accident (AVC) (diagnosed between the 20th week of fetal life and the 28th day of life including in premature newborns). Cerebral growth anomalies: microcephaly with cranial perimeter <- 2 SD at birth verified secondarily or macrocephaly> + 3 SD for the term (persisting after a second measurement). A family history of severe first-degree neurodevelopmental disorder (brother or sister or parent) Symptomatic congenital cytomegalovirus infections and other infectious fetopathies: toxoplasmosis, Zika, rubella, etc. Bacterial and viral herpetic meningoencephalitis Complex congenital heart disease operated on: transposition of the large vessels; left ventricular hypoplastic syndrome. Perinatal exposure to a major toxicant: certain antiepileptics (sodium valproate); severe exposure to alcohol and / or with signs of fetal disease. Major, prolonged and repeated surgery (cardiac, cerebral, abdominal, thoracic). Exclusion of all deficiency forming part of a polymalformative, vascular syndrome (Poland syndrome), genetic cause ... Exclusion of all other forms of agenesis (bilateral, longitudinal, persistence of hand remains), Refusal of consent from one or both parents