Limb and Digit Malformations

What is the primary cause of Amelia?

Which condition is characterized by hands or feet being attached close to the body?

What type of syndactyly involves the fusion of bones?

Which condition is typically inherited as a dominant trait and causes short fingers or toes?

What genetic defect is associated with Ectrodactyly?

What is the consequence of Congenital Absence of the Radius?

What causes Amniotic Band Syndrome?

What is a key feature of Osteogenesis Imperfecta?

What is the condition characterized by the complete absence of a limb?

Which malformation involves fusion of digits due to failure of digital ray notches to form?

What condition is associated with the presence of extra digits and is typically inherited as a dominant trait?

Which syndrome is caused by the rupturing or tearing of the amnion during fetal development?

Marfan Syndrome is primarily associated with mutations in which gene?

What is characterized by short fingers or toes due to reduced length of phalanges?

In which condition do the hands or feet attach close to the body due to severe disruption in limb development?

Osteogenesis Imperfecta is primarily linked to mutations in which type of genes?

Limb Malformations

Amelia: Complete absence of a limb
Meromelia: Partial absence of a limb
Phocomelia: Hands or feet attached directly to the body, caused by severe disruption in limb development during week 5
- Often caused by teratogens like thalidomide
Micromelia: Proportionally small limbs, caused by general failure in limb growth during development

Digit Malformations

Syndactyly: Fusion of digits
- Cutaneous Syndactyly: Failure of skin webbing between digits to disappear
- Osseous Syndactyly: Failure of digital ray notches to form leading to fusion of bones
Brachydactyly: Short fingers or toes due to reduced length of phalanges, often inherited
Polydactyly: Extra digits, often inherited
Ectrodactyly: Absence of one or more fingers or toes, caused by a defect in the TP63 gene affecting digital ray development during weeks 5-6

Other Skeletal Malformations

Cleft Hand & Foot (Split-Hand/Foot Malformations): Absence of central digits and a split appearance of the hand or foot, caused by failure in the development of one or more digital rays during weeks 5-6
- Autosomal dominant with incomplete penetrance
Osteogenesis Imperfecta: Weak bone structure and frequent fractures during fetal development, caused by mutations in collagen-producing genes (COL1A1 and COL1A2)
Marfan Syndrome: Overgrowth of long bones and skeletal abnormalities, caused by mutations in the FBN1 gene leading to defective fibrillin-1 protein and affecting connective tissue development
Congenital Absence of the Radius: Partial or complete absence of the radius, caused by failure of the mesenchymal primordium of the radius to form during week 5
- Leads to lateral deviation of the hand and bowing of the ulna

Amniotic Band Syndrome (ABS)

Amniotic Band Syndrome (ABS): Caused by exogenous factors such as rupturing or tearing of the amnion during fetal development
- Leads to the formation of encircling amniotic bands that can constrict fetal tissues, resulting in defects ranging from digital constriction to major craniofacial and visceral abnormalities

Explore a variety of congenital malformations affecting limbs and digits, including amelia, syndactyly, and polydactyly. This quiz delves into the causes, characteristics, and implications of these conditions, enhancing your understanding of developmental anomalies. Perfect for students and professionals in medical fields.