Congenital familial hypoplastic thumb associated with congenital amputation of the toe

Area of Science:

• Genetics and Developmental Biology
• Orthopedics and Hand Surgery
• Clinical Case Reports

Background:

• Congenital anomalies of the upper and lower extremities present a spectrum of developmental abnormalities.
• Hypoplastic thumb, specifically Blouth type 1, involves underdeveloped thenar muscles and thumb structures.
• Syndromic associations of limb malformations require thorough investigation for genetic and clinical significance.

Observation:

• A family presented with a rare co-occurrence of congenital hypoplastic thumb (Blouth type 1) and congenital amputation of the first toe.
• Affected individuals exhibited hypoplastic thenar muscles, absence of the first toe, syndactyly (webbing) between the second and third toes, and brachymesophalangia (shortening) of the 2nd and 5th proximal phalanges.
• No cardiovascular defects were noted in the affected mother and daughter.

Findings:

• The family members demonstrated a consistent pattern of limb malformations, suggesting a potential genetic basis.
• A characteristic metacarpophalangeal pattern profile was observed, aiding in the classification and understanding of the skeletal anomalies.
• This specific combination of thumb hypoplasia and first toe amputation is novel and previously unreported in medical literature.

Implications:

• This case report expands the known spectrum of congenital limb malformations.
• Further research into the genetic etiology of this specific limb malformation syndrome is warranted.
• Understanding such rare conditions aids in genetic counseling and clinical management of affected families.