Achard syndrome

Achard syndrome is a syndrome consisting of arachnodactyly, receding lower jaw, and joint laxity limited to the hands and feet. Hypermobility and subluxations of the joints, increased lateral excursion of the patellas and other findings reflect the increased ligament laxity. It is not clear if it is a distinct entity.
Symptoms

Small thumbs
Joint laxity in hands
Joint laxity in feet
Brachycephaly
Short mandibular rami

References

Achard C (1902). "Arachnodactylie". Bull. Mem. Soc. Med. Hop. Paris 19: 834–840. 
Duncan PA (1975). "The Achard syndrome". Birth Defects Orig Artic Ser 11 (6): 69–73. PMID 1201353. 
PARISH JG (1960). "Skeletal syndromes associated with arachnodactyly". Proc R Soc Med 53: 515–8. PMC 1870110. PMID 14430455. 
Parish JG (1967). "Skeletal hand charts in inherited connective tissue disease". J Med Genet
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