brachydactyly type A4

Brachydactyly type A4, also known as Temtamy type or brachymesophalangy II and V, is a rare congenital limb malformation characterized by short middle phalanges in the 2nd and 5th fingers. This condition is typically inherited in an autosomal dominant pattern, meaning that a single copy of the mutated gene is enough to cause the condition.

In individuals with brachydactyly type A4, the middle phalanx of the second finger (index finger) and the fifth finger are usually affected, resulting in shortening of these digits. The fourth finger may also exhibit middle phalanx shortening and radial curvature. This condition is often isolated, but it can also occur as part of a complex malformation syndrome.

Brachydactyly type A4 is caused by genetic mutations, which can be hereditary or occur randomly. It's essential to note that this condition does not typically affect the functionality of the fingers or toes; instead, it is primarily a cosmetic concern.

References:

• [4] Brachydactyly type A4 or Temtamy type is characterized by brachymesophalangy (absent or hypoplastic middle phalanx) of the second and fifth fingers.
• [5] Brachydactyly type A4 is a rare congenital limb malformation characterized by short middle phalanges in the 2nd and 5th fingers, and absence of middle phalanges ...
• [6] Brachydactyly type A4 (BDA4) is a congenital malformation characterized by brachymesophalangy II and V or Temtamy-type brachydactyly and has been reported in a few families with shortening of the middle phalanges of the second and fifth fingers.
• [14] Brachydactyly type A4 (BDA4) is also known as brachymesophalangy II and V or Temtamy type brachydactyly and has been reported in a few families with shortening of the middle phalanges of the second and fifth fingers.

Common Signs and Symptoms of Brachydactyly Type A4

Brachydactyly type A4 (BDA4) is a congenital malformation characterized by shortening of the middle phalanges, particularly affecting the 2nd and 5th digits. The symptoms can vary in severity, but here are some common signs associated with BDA4:

• Shortened middle phalanges: The most distinctive feature of BDA4 is the shortening of the middle phalanges, which can be complete or partial.
• Bifid distal phalanx of thumb: In some cases, the distal phalanx of the thumb may appear bifid (split) and have nail dysplasia [3].
• Nail dysplasia: The nails on the affected digits may be small, thin, or absent.
• Shortened fingers: The fingers can be significantly shorter than normal, with the middle phalanges being particularly affected.
• Broadening of the distal phalanx: In severe cases, the distal phalanx may appear broadened due to the absence or hypoplasia of the middle phalanx [4].

Other Associated Features

While not exclusive to BDA4, some individuals with this condition may also experience:

• Club foot: A less common feature associated with BDA4.
• Clinodactyly: A curvature of the little finger or other digits.
• Ulnar deviation of the second finger: The second finger may be deviated towards the ulna (outer bone) [1].

References

[1] Mar 8, 2024 — Other less common features include club foot, clinodactyly, ulnar deviation of the second finger. [3] by A David · 2015 · Cited by 17 — Type A4 is shortened middle phalanx together with bifid appearance of distal phalanx of thumb as well as nail dysplasia [3]. [4] by SA Temtamy · 2008 · Cited by 192 — In the severe variety, the fingers are about half of the normal length, the middle phalanges of all digits are either absent or very hypoplastic ...

Brachydactyly type A4 can be diagnosed through various diagnostic tests, which may include:

• Molecular or cytogenetic tests to detect genetic abnormalities [3][10]
• Radiological tests to assess the bone structure and identify any abnormalities [4][6][15]
• Clinical evaluation by a healthcare professional to observe the physical characteristics of brachydactyly type A4 [1][5]

These diagnostic tests can help establish an etiological diagnosis, which is essential for determining the underlying cause of the condition. In some cases, brachydactyly may be an isolated condition, while in others it may be part of a complex malformation syndrome [3].

It's worth noting that prenatal diagnosis is usually not indicated for isolated forms of brachydactyly, but may be considered if there are other associated abnormalities [6]. Additionally, genetic counseling and testing may be recommended to identify any inherited mutations or risk factors [7][14].

References:

[1] Context result 4: Brachydactyly is a medical term denoting the presence of abnormally short digits (fingers or toes) at birth. [3] Context result 3: A test (molecular or cytogenetic test, or both) to detect a genetic abnormality will further establish the etiological diagnosis. [4] Context result 9: Brachydactyly is characterized by shortening of the distal phalanges, nail dysplasia and clinodactyly of the 5th digit. [5] Context result 1: Brachydactyly type A4 is caused by genetic mutations, also known as pathogenic variants. [6] Context result 6: Diagnosis is clinical, anthropometric and radiological. Prenatal diagnosis is usually not indicated for isolated forms of brachydactyly, but may ... [7] Context result 14: Important. You have the possibility to add isolated genes in addition to your selection, directly on the test request form. [10] Context result 10: test (molecular or cytogenetic test, or both) to detect a genetic abnormality will further establish the etiological diagnosis. [15] Context result 15: Brachydactyly type A4 is a rare congenital limb malformation characterized by short middle phalanges in the 2nd and 5th fingers, and absence of middle phalanges ...

Differential Diagnosis of Brachydactyly Type A4

Brachydactyly type A4, also known as Bell's classification, is a rare congenital limb malformation characterized by short middle phalanges in the 2nd and 5th fingers. When diagnosing this condition, it is essential to consider other possible causes of short digits that may present similarly.

Possible Differential Diagnoses:

• Pseudohypoparathyroidism (PHP): A genetic disorder characterized by short stature, round face, and short fourth metacarpals [5].
• Kirner deformity: A rare congenital anomaly involving a flexion contracture of the little finger, often associated with nail dysplasia [6].
• Camptodactyly: A congenital condition where one or more fingers are permanently bent at the joint, which can be mistaken for brachydactyly type A4 [7].
• Brachymesophalangy II-V (Temtamy type): Another rare form of brachydactyly that affects the middle phalanges of the 2nd and 5th fingers, similar to brachydactyly type A4 [8].
• Catel-Manzke syndrome: A rare genetic disorder characterized by short stature, facial abnormalities, and limb malformations, including brachydactyly [9].

Clinical and Radiological Findings

The diagnosis of brachydactyly type A4 is primarily based on clinical and radiological findings. A thorough medical history, physical examination, and imaging studies (such as X-rays) are essential to rule out other possible causes of short digits.

In conclusion, when diagnosing brachydactyly type A4, it is crucial to consider the differential diagnoses mentioned above to ensure accurate diagnosis and treatment planning.

References:

• [8] Orphanet summary: Brachymesophalangy II-V (Temtamy type)
• [9] H. Reichenbach, D. Hörmann, H. Theile: Brachydactyly type A4 (brachymesophalangia II and V, Temtamy type). A rare type of brachydactyly.
• [11] Table 5.59 Classification of isolated brachydactyly; Type. Findings. Comments. A1. ... A4. Short middle phalanges: second and fifth.