Related Experiment Video

Updated: Feb 8, 2026

A Method to Study the C924T Polymorphism of the Thromboxane A2 Receptor Gene

A Method to Study the C924T Polymorphism of the Thromboxane A2 Receptor Gene

Published on: April 1, 2019

Association between androgen receptor polymorphic CAG and GGC repeat lengths and cryptorchidism: A meta-analysis of

Y Wang¹, Y Wei¹, X Tang¹

¹Department of Urology, Children's Hospital of Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Children's Urogenital Development and Tissue Engineering, China.

Journal of Pediatric Urology

|June 20, 2018

Abstract

Introduction:

Previous studies have revealed the relationship between androgen receptor (AR) CAG and/or GGC polymorphisms and risk of cryptorchidism, yet the results have been elusive and controversial.

Aim:

To determine whether AR polymorphic CAG and/or GGC repeats are related to cryptorchidism.

Study Design:

The relevant studies were obtained from PubMed, Embase, China National Knowledge Infrastructure, and Wanfang. The pooled odds ratios with 95% confidence intervals (CIs) were used to assess the strength of associations. Subgroup analyses were performed based on ethnicity and source of controls. Moreover, Begg's funnel plots and Egger's linear regression test were conducted to determine publication bias.

Results:

Eight case-control studies containing 321 patients and 784 normal controls were included. There was a significant association between longer CAG repeats and cryptorchidism risk (weighted mean difference (WMD) = 0.62; 95% CIs 0.06, 1.18; P = 0.031). Moreover, there was a significant association between the longer GGC repeats and cryptorchidism risk (WMD = 0.87; 95% CIs 0.04, 1.74; P = 0.040). There was significant association between the longer CAG repeats and bilateral cryptorchidism (WMD = 0.88; 95% CIs -0.18, 1.94; P = 0.011), while there was no significant association between the longer CAG repeats and unilateral cryptorchidism (WMD = -0.09; 95% CIs -0.50, 0.31; P = 0.554). There were significant associations between the longer GGC repeats and unilateral cryptorchidism (WMD = 0.88; 95% CIs -0.30, 2.05; P = 0.005) and bilateral cryptorchidism (WMD = 1.35; 95% CIs -0.52, 3.21; P = 0.000). Stratifying analysis revealed an association between longer CAG/GGC repeats and cryptorchidism in Caucasian populations from Europe (WMD = 0.73; 95% CIs 0.00, 1.46; P = 0.017), while there was no association with Asian populations.

Discussion:

This meta-analysis found that CAG/GGC repeats in the AR gene were longer in cryptorchidism patients compared to controls. Both the longer CAG repeats and GGC repeats in the AR gene were associated with cryptorchidism risk. The longer CAG repeats were associated with bilateral cryptorchidism, whereas the longer GGC repeats were associated with unilateral and bilateral cryptorchidism. Stratifying analysis revealed an association between longer CAG/GGC repeats and cryptorchidism in Caucasian populations from Europe, while there was no association between longer CAG/GGC repeats and cryptorchidism in Asian populations.

Conclusion:

The CAG/GGC repeats in the AR gene were longer in cryptorchidism than in controls. Longer CAG repeats may play a role in determining bilateral cryptorchidism, and longer GGC repeats may play a role in determining unilateral and bilateral cryptorchidism. These observations were more applicable to Caucasian populations.

Keywords:

Androgen receptor CAG repeats Cryptorchidism GGC repeats Gene Meta-analysis

More Related Videos

Meta-analysis of Voxel-Based Neuroimaging Studies using Seed-based d Mapping with Permutation of Subject Images SDM-PSI

Meta-analysis of Voxel-Based Neuroimaging Studies using Seed-based d Mapping with Permutation of Subject Images SDM-PSI

Published on: November 27, 2019

Author Spotlight: Evaluating the Adjuvant Efficacy and Safety of Angong Niuhuang Pill in Viral Encephalitis Treatment

Author Spotlight: Evaluating the Adjuvant Efficacy and Safety of Angong Niuhuang Pill in Viral Encephalitis Treatment

Published on: April 19, 2024

Related Concept Videos

Internal Receptors

Internal Receptors

Many cellular signals are hydrophilic and therefore cannot pass through the plasma membrane. However, small or hydrophobic signaling molecules can cross the hydrophobic core of the plasma membrane and bind to internal, or intracellular, receptors that reside within the cell. Many mammalian steroid hormones use this mechanism of cell signaling, as does nitric oxide (NO) gas.

Interference: Path Lengths

Interference: Path Lengths

Consider two sources of sound, that may or may not be in phase, emitting waves at a single frequency, and consider the frequencies to be the same.
Two special sources may be considered when they are in phase. This can be easily achieved by feeding the two sources from the same source. An example would be synchronizing the two speakers by feeding them with the same source, such as the sound waves produced by a tuning fork. This setup ensures that the two sources have the same frequency and are...

Genome-wide Association Studies-GWAS

Genome-wide Association Studies-GWAS

Genome-wide association studies or GWAS are used to identify whether common SNPs are associated with certain diseases. Suppose specific SNPs are more frequently observed in individuals with a particular disease than those without the disease. In that case, those SNPs are said to be associated with the disease. Chi-square analysis is performed to check the probability of the allele likely to be associated with the disease.
GWAS does not require the identification of the target gene involved in...

Bond Energies and Bond Lengths

Bond Energies and Bond Lengths

Stable molecules exist because covalent bonds hold the atoms together. The strength of a covalent bond is measured by the energy required to break it, that is, the energy necessary to separate the bonded atoms. Separating any pair of bonded atoms requires energy — the stronger a bond, the greater the energy required to break it.

Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches

Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches

Biopharmaceutical studies constitute a vital field aiming to enhance drug delivery methods and refine therapeutic approaches, drawing upon diverse interdisciplinary knowledge. In research methodologies, the choice between controlled and non-controlled studies significantly influences the study's reliability and accuracy.
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...

Directing Effect of Substituents: meta-Directing Groups

Directing Effect of Substituents: meta-Directing Groups

Substituents on the benzene ring that direct an incoming electrophile to undergo substitution at the meta position are called meta directors. All meta directors either have a positive charge on the atom directly bonded to the ring or a partial positive charge. These groups function by withdrawing electrons from the ring through inductive and resonance effects. Consider the carbocation intermediates formed upon the addition of an electrophile on nitrobenzene at the...

Articles linked to this work by shared authors, journal, and citation graph.

Plasmid DNAs encoding insulin and glutamic acid decarboxylase 65 have distinct effects on the progression of autoimmune diabetes in nonobese diabetic mice.

Journal of immunology (Baltimore, Md. : 1950)·2001

[Study of the cytotoxity against human hepatocellular carcinoma cells induced by the MAGE-1 gene modified dendritic cells].

Zhonghua gan zang bing za zhi = Zhonghua ganzangbing zazhi = Chinese journal of hepatology·2001

Differential effects of protein kinase C on human vascular smooth muscle cell proliferation and migration.

American journal of physiology. Heart and circulatory physiology·2001

Anodic cyclization reactions: reversing the polarity of ketene dithioacetal groups.

Organic letters·2001

Assessment of total energy expenditure in a Chinese population by a physical activity questionnaire: examination of validity.

International journal of food sciences and nutrition·2001

Downregulation of the ERK 1 and 2 mitogen activated protein kinases using antisense oligonucleotides inhibits proliferation of porcine vascular smooth muscle cells.

Atherosclerosis·2001

See all related articles