Related Experiment Video
Updated: Jun 10, 2026
09:42
Development of a Neonatal Rat Model for Brachial Plexus Birth Injury
Published on: March 27, 2026
Sirenomelia
Rabia Akhtar1, Yasmeen Humayun
1Department of Diagnostic Radiology/Obstetrics and Iqbal Memorial Hospital, Kharian. rabia1096@hotmail.com
Summary
This case report details sirenomelia, a rare congenital anomaly, diagnosed postnatally. Prenatal ultrasound revealed key indicators like a fetal kidney cyst and anhydramnios, aiding in understanding this condition.
Area of Science:
- Medical Science
- Pediatrics
- Medical Imaging
Background:
- Sirenomelia, a rare congenital anomaly characterized by the fusion of lower limbs, presents significant diagnostic challenges.
- Understanding the spectrum of associated anomalies is crucial for comprehensive patient management.
Observation:
- A neonate presented with a single lower limb, absent feet, anal atresia, and absent external genitalia.
- Prenatal ultrasound identified a left renal cyst, anhydramnios, and a high resistive index (RI) in the fetal umbilical artery.
Findings:
- Postnatal morphological and radiographic examination confirmed the diagnosis of sirenomelia.
- The observed prenatal ultrasound findings correlate with documented indicators for sirenomelia.
Implications:
- This case highlights the importance of detailed prenatal ultrasound in diagnosing rare congenital malformations like sirenomelia.
- Early identification through advanced imaging techniques can facilitate timely intervention and improve outcomes for affected infants.
Related Concept Videos
01:21Nondisjunction
Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate correctly and move to the opposite poles of the cells. This produces daughter cells with abnormal chromosome numbers. Nondisjunction is common during anaphase I or anaphase II of meiosis. Mutations in synaptonemal complex proteins that attach homologous chromosomes increase the chances of nondisjunction in anaphase I of meiosis I. In contrast, mutations in topoisomerases and condensins that hold sister...
01:29Nondisjunction
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.
02:30Genomic 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...
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
01:30Neurulation
Neurulation is the embryological process which forms the precursors of the central nervous system and occurs after gastrulation has established the three primary cell layers of the embryo: ectoderm, mesoderm, and endoderm. In humans, the majority of this system is formed via primary neurulation, in which the central portion of the ectoderm—originally appearing as a flat sheet of cells—folds upwards and inwards, sealing off to form a hollow neural tube. As development proceeds, the anterior...
01:49Meiosis I
Meiosis is a carefully orchestrated set of cell divisions, the goal of which—in humans—is to produce haploid sperm or eggs, each containing half the number of chromosomes present in somatic cells elsewhere in the body. Meiosis I is the first such division, and involves several key steps, among them: condensation of replicated chromosomes in diploid cells; the pairing of homologous chromosomes and their exchange of information; and finally, the separation of homologous chromosomes by a...
01:15Development of the Sexual Organs in the Embryo and Fetus
Development of the reproductive organs in an embryo starts from a bipotential state. This means the early embryo can develop either male or female reproductive organs. The formation of these organs begins with the growth of gonadal ridges that arise from the intermediate mesoderm during the fifth week of development.
Near the gonadal ridges, two duct systems are present: the mesonephric ducts (Wolffian ducts) and paramesonephric ducts (Müllerian ducts). These ducts form the basis for the male...
Near the gonadal ridges, two duct systems are present: the mesonephric ducts (Wolffian ducts) and paramesonephric ducts (Müllerian ducts). These ducts form the basis for the male...