BACKGROUND: 3-M syndrome is an uncommon disease characterized by severe growth retardation, dysmorphic features, and skeletal abnormalities. Radiographic images may show delayed bone maturation long slender tubular bones, and tall vertebral bodies. Due to the inheritance mode of 3-M syndrome disease, early diagnosis is vital for genetic counseling.

CASE REPORT: In this case report, we present the case of a 3-year-old male patient who was referred to our clinic for development assessment due to delayed development, particularly speech, who had clinical outcomes of 3-M syndrome.

CONCLUSIONS: The aim of the case report is to add this new patient to the literature on 3-M syndrome.

Keywords: Lead Poisoning, Nervous System, Childhood, Musculoskeletal Abnormalities, Pediatric Assistants, Atrophy, Brain Stem, Cerebellum, Child, Preschool, Cullin Proteins, Developmental Disabilities, Dwarfism, genetic variation, Homozygote, Muscle Hypotonia, Spine