Some limb malformations are known to be sporadic (non hereditary). For these malformations, no molecular cause was identified, even after whole genome sequencing. Methylation of CpG islands is an epigenetic process which is usually not transmitted to the descents. We hypothesize that sporadic limb malformations may be due to a methylation anomaly. This study will include patients with Amelia or Femur Fibula Ulna Syndrome. With patients consent, we will study the methylome on DNA samples already available in our laboratory. Each patient sample will be paired to a control of same tissue, age and sex. By bioinformatics comparison, we will identify differentially methylated candidate regions.

Inclusion Criteria:

• Specific consent for this study
• DNA available in the laboratory
• For amelia : agenesia of 2 or 4 limbs
• For Femur-Fibula-Ulna Syndrome : hypoplasia or agenesia of the femur uni or bilateral with hypoplasia or agenesia or bowing of the fibula and/or of the ulna

Exclusion Criteria:

• No consent
• No available DNA or poor quality of the DNA sample
• Patient under tutorship
• Pregnancy or nursing mother
• Patient non covered by the French social security

DNA samples were obtained from the molecular biology laboratory of Lille university hospital. All patients exhibiting amelia or Femur-Fibula-Ulna Syndrome and with enough DNA available in the lab could be included.