Clefting, amniotic bands, and polydactyly: a distinct phenotype that supports an intrinsic mechanism for amniotic

Nathaniel H Robin1, Judith Franklin, Sandra Prucka

  • 1Department of Genetics, University of Alabama at Birmingham, 35294-0024, USA. nrobin@uab.edu

Insights

Amniotic band sequence (ABS) can present with birth defects beyond limb constriction, like cleft lip and palate (CLP). This case suggests a potential new syndrome overlapping with ABS, possibly linked to genetic factors.

Area of Science:

  • Developmental Biology
  • Medical Genetics

Background:

  • Amniotic band sequence (ABS) is characterized by congenital anomalies due to fibrous bands disrupting fetal development.
  • While ABS typically involves limb defects, its association with other anomalies like cleft lip and palate (CLP) is not fully explained by the entanglement mechanism.

Observation:

  • This report details a case with classic ABS limb defects and constriction bands.
  • The patient also presented with typical cleft lip and palate (CLP), a supernumerary nipple, polydactyly, and a skin papilla.

Findings:

  • The observed constellation of anomalies closely resembles a previously reported case, suggesting a potential distinct syndrome overlapping with ABS.
  • This presentation challenges the traditional understanding of ABS etiology.

Implications:

  • The findings suggest that ABS-like anomalies coupled with CLP may represent a separate condition, potentially linked to genetic mutations.
  • Further research into genes such as Disorganization, p63, or IRF6 is warranted to elucidate the underlying causes.

Related Concept Videos

Cleavage and Blastulation01:33

Cleavage and Blastulation

After a large-single-celled zygote is produced via fertilization, the process of cleavage occurs while zygotes travel through the uterine tube. Cleavage is a mitotic cell division that does not result in growth. With each round of successive cell division, daughter cells get increasingly smaller.
Polytene Chromosomes02:04

Polytene Chromosomes

Polytene chromosomes are giant interphase chromosomes with several DNA strands placed side by side. They were discovered in the year 1881 by Balbiani in salivary glands, intestine, muscles, malpighian tubules, and hypoderm of larvae Chironomus plumosus. Hence, these are also called "Salivary gland chromosomes." These are found in insects of the order Diptera and Collembola; in certain organs of mammals; and synergids, antipodes of flowering plants. Polytene chromosomes are also regularly...
Genomic Imprinting and Inheritance02:30

Genomic Imprinting and Inheritance

Diploid organisms inherit genetic material through chromosomes from both parents. Copies of the same gene are known as alleles. In most cases, both alleles are simultaneously expressed and allow various cellular processes to function optimally. If one of the alleles is missing or mutated, the expression of the other allele can compensate; however, this is not true for all genes.
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
Lampbrush Chromosomes01:51

Lampbrush Chromosomes

In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, Rückert observed LBCs in shark egg cells and coined the term "lampbrush chromosomes" because they looked like brushes used to clean kerosene lamps.
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops resemble the...
Pleiotropy01:33

Pleiotropy

Pleiotropy is the phenomenon in which a single gene impacts multiple, seemingly unrelated phenotypic traits. For example, defects in the SOX10 gene cause Waardenburg Syndrome Type 4, or WS4, which can cause defects in pigmentation, hearing impairments, and an absence of intestinal contractions necessary for elimination. This diversity of phenotypes results from the expression pattern of SOX10 in early embryonic and fetal development. SOX10 is found in neural crest cells that form melanocytes,...
Nondisjunction01:29

Nondisjunction

During meiosis, chromosomes occasionally separate improperly. This occurs due to failure of homologous chromosome separation during meiosis I or failed sister chromatid separation during meiosis II. In some species, notably plants, nondisjunction can result in an organism with an entire additional set of chromosomes, which is called polyploidy. In humans, nondisjunction can occur during male or female gametogenesis and the resulting gametes possess one too many or one too few chromosomes.