Homozygous deletion of an 80Â kb region comprising part of DNAJC6 and LEPR genes on chromosome 1P31.3 is associated with early onset obesity, mental retardation and epilepsy

► Homozygous deletion of an 80 kb region (1p31.3) including LEPR and DNAJ6C genes. ► A human case of leptin receptor long isoform deficiency with preserved short forms. ► The leptin receptor short isoforms are not sufficient to prevent obesity in humans. ► First reported loss-of-function mutation for endospanin-1 in humans. ► Auxilin-1 as a new candidate for mental retardation and epilepsy.