Related Experiment Video

Updated: Aug 18, 2026

A Strategy to Identify de Novo Mutations in Common Disorders such as Autism and Schizophrenia
05:51

A Strategy to Identify de Novo Mutations in Common Disorders such as Autism and Schizophrenia

Published on: June 15, 2011

Maternal origin of inv dup(15) chromosomes in infantile autism

T Martinsson1, T Johannesson, M Vujic

  • 1Department of Clinical Genetics, Göteborg University, East Hospital, Sweden.

European Child & Adolescent Psychiatry
|December 1, 1996
PubMed

Insights

The extra inverted duplicated chromosome 15 (inv dup(15)) in infantile autism patients originated from the mother. This genetic marker arose during maternal meiosis, not early embryonic development.

Area of Science:

  • Genetics
  • Developmental Biology
  • Neurodevelopmental Disorders

Background:

  • Infantile autism is associated with chromosomal abnormalities.
  • Previous studies identified an extra inverted duplicated chromosome 15 [inv dup(15)] in male patients with infantile autism.
  • This extra chromosome involves four copies of the 15pter-q13 region.

Purpose of the Study:

  • To investigate the parental origin of the inv dup(15) chromosome.
  • To determine the timing of the origin of the inv dup(15) chromosome.
  • To propose a model for the formation of this chromosomal abnormality.

Main Methods:

  • Analysis of DNA from families of four patients with infantile autism and inv dup(15).
  • Utilized Southern-based Restriction Fragment Length Polymorphisms (RFLPs).
  • Employed microsatellite polymorphisms specific to the 15pter-q13 region.

Main Results:

  • The inv dup(15) chromosome was confirmed to be of maternal origin in all four analyzed cases.
  • Molecular data indicates the origin occurred during maternal meiosis.
  • The extra chromosome contained genetic material from both maternal chromosome 15 homologs.

Conclusions:

  • The maternal meiotic process is the likely source of the inv dup(15) in these patients.
  • The findings challenge an origin during early embryonic mitosis.
  • A model for the origin of such maternal chromosomal markers is proposed.

More Related Videos

Rapid Detection of Neurodevelopmental Phenotypes in Human Neural Precursor Cells (NPCs)10:47

Rapid Detection of Neurodevelopmental Phenotypes in Human Neural Precursor Cells (NPCs)

Published on: March 2, 2018

Dynamic Clamp Methods to Investigate Impaired Neuronal Excitability Associated with Autism08:44

Dynamic Clamp Methods to Investigate Impaired Neuronal Excitability Associated with Autism

Published on: October 17, 2025

Related Concept Videos

Meiosis I01:49

Meiosis 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...
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.
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...
Meiosis I03:09

Meiosis I

Meiosis is the division of a diploid cell into haploid cells forming sperm and eggs in animals through differentiation. Meiosis I is the first stage of meiosis, where the genetic recombination of homologous chromosomes and the reduction of the ploidy level by half occurs.
Prophase I is the most extended and complex step of meiosis I characterized by synapsis, chromosome pairing, and recombination of the homologous chromosomes. This process is facilitated by a proteinaceous structure called the...
Nondisjunction01:21

Nondisjunction

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...
Autism Spectrum Disorder01:19

Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a neurodevelopmental condition marked by persistent deficits in social communication and interaction alongside restrictive and repetitive behaviors or interests. ASD is sometimes accompanied by intellectual impairment.
These core symptoms manifest differently among individuals, ranging from mild to severe. The disorder's complexity extends beyond its clinical presentation, encompassing a diverse range of biological, cognitive, and sociocultural influences.