3-M syndrome or 3M3 is a rare hereditary disorder characterized by severe growth retardation, facial dysmorphia, and skeletal abnormalities.

[1] The name 3-M is derived from the initials of the three researchers who first identified it: Miller, McKusick, and Malvaux and report their findings in the medical literature in 1972.

Treatment is aimed at addressing the growth and skeletal problems and may include surgical bone lengthening, adaptive aids, and physical therapy.

[6] Growth delays and immature bone development (growth retardation and delayed bone maturation) typically continue after birth (postnatally), leading to short stature (dwarfism) with proportional development of the arms and legs (as opposed to short stature with abnormally small arms and legs).

[6][4][8] Infants with this disorder may also have abnormally flat cheeks and cheekbones, large ears, prominent mouth with widely spread lips, and or underdeveloped upper jaw bones (maxillary hypoplasia).

[6][4][8] In some cases, males have been reported to have impaired fertility due to the reduced production of sex hormones and hypospadias which is when the opening of the urethra is on the underside of the penis instead of the tip.

[2][9] Disruption of the protein degradation process plays a role in the pathogensis of prenatal growth retardation in humans, a key feature of 3-M syndrome.

[9] The skeletal abnormalities that are present in individuals with this disorder suggests that this gene may play a role in the endochondral ossification process.

[1] Due to the fact that many of the abnormalities associated with this disorder are congenital, the presence of these clinical features at birth is usually sufficient to make the diagnosis.

[8] Diagnosis is suggested in children with the following: low birth weight, severe growth retardation, typical facial features, and characteristic radiological findings.

[12] In some cases, growth retardation and/or other characteristic findings suggestive of Three M syndrome may be detected before birth by ultrasound.

[6] Treatment may involve the coordinated efforts of many healthcare professionals, such as pediatricians, orthopedists, dentists and/or other specialists depending on the symptoms.

Family members of affected individuals should also receive regular clinical evaluations to detect any symptoms and physical characteristics that may be potentially associated with Three M syndrome or heterozygosity for the disorder.