This document discusses several topics related to genetics and microbiology. It begins by summarizing the central dogma of genetics, then discusses a study that identified mutations in the AFF2 gene on the X chromosome that increase autism risk, particularly in boys. It also describes how the enzyme RNase R in bacteria is responsible for RNA processing, and could be a target for new antibiotics. In closing, it emphasizes how molecular biology research into mechanisms like these can advance medical understanding and treatment of conditions like autism and bacterial infections.

1. Laura Valentina López Gutiérrez
Medical Student

4. INTRODUCTION
 The central dogma of
genectic information is:
DNA RNA PROTEINS
 RNA
 RNAm: mould for protein
synthesis
 RNAr: component of the
ribosomes
 RNAt: aligns the aminoacids
along the RNAm

5. Mutations in Autism
Susceptibility Gene
Increase Risk in
Boys
 Researchers identified five diferent
and rare mutations in a gene, these
increase the chances that a children
develop an ASD.
 The presence of intellectual disability
with autistic features, is responsibility
of the elimination or silence of AFF2
gene.

6. Autism Spectrum Disorder (ASD)
 ASD is a disability that
causes problems with social
interaction, they can´t have a
verbal communication, nor
non-verbal communication,
also they have routines or
repetitive behaviors. ASD can
be associated with difficulties
in motor coordination and
attention and physical health
like sleep and gastrointestinal
disturbances.

7. AFF2 Gene
 The AFF2 gene and others
like that, are ubicated in the
chromosome X, that reason
explains why Autism
Spectrum Disorders affect
four times more to boys
than to girls, because the
♂ ♀ girls have other copy of this
chromosome that can
compensate if there is a
mutation in one of both.
XY XX

8. Mutations
 A mutation is the alteration in the DNA
sequence, which can range from changing a
nitrogenous base, to the deletion of a
chromosome or gain a full chromosome.
Those can be:
*Deletion
*Translocation
*Duplication
*Inversion
*Polyploidy
*Change of bases

9. PERSONAL COMENTARY
 Discovering this mutation in the gene AFF2 is
very important, because this may explain
many cases of children with ADS, and can
determine the inheritance of the gene. It is
very important as it will open up ways to
discover, if there are more genes located on
chromosome X associated with this disease

10. Unique Mechanism Identified
in Bacteria as Potential
Target for Developing New
Antibiotics
 Researchers have discovered
that the enzyme RNasa R is
responsible for making RNA
processing 3 ', a necessary
step for the synthesis of
proteins of bacteries. This
enzyme eliminates the
additional parts of a tRNA
precursor to make it functional.
Thus the follows researches
will focus on blocking this
protein.

11. RNAt
 In the synthesis of proteins,
each aminoacid must be
aligned with a corresponding
codon of the RNAm mold.
The RNA transfer serves as
the adapter of this process.
The RNAm sequence is
recognized by the anticodon
located at one end of the
molecule, at the other end is
located the aminoacid, and
thus are united one by one
by peptide bonds.

12. Mycoplasma Genitalium
 One such pathogen is the
bacterium Mycoplasma
genitalium, which is the
second smallest known
free-living organism that is
thought to cause infertility,
urethritis and cervicitis in
women.

13. Antibiotics
 An antibiotic is a
chemical substance
produced by a
microorganism and
therefore has a natural
origin, that suppresses
the growth of other
microorganisms and may
eventually destroy them,
so it is effective for the
treatment of infections
caused by internal body
such germs, mainly
bacterial infections .

14. PERSONAL COMENTARY
 It is comforting that through molecular biology,
the researches do findings so important like
the mechanisms used by bacteria to live, and
thus know how to attack them, specifically the
mechanisms of action of their enzymes,
inhibiting protein synthesis, a process required
for replication.

15. MEDICAL UTILITY
 Autism is a disability that
limits the socialization and
development of the mental
processes of the individual,
now to they found the gene in
which mutation develops the
ADS, allows scientifically
advance in the genetic
management for early
diagnosis of this disease, and
treatment advice to improve
the quality of life of people
with autism and their families.

16. MEDICAL UTILITY
 This discovery is a interesting and big step in
the searching of causes in autism spectrum
disorder (ASD), because these mutations
found in this study explain 20% of cases of
the boys with the disorder. Also I believe is
very important the following studies that they
are going to do about this topic, the
researchers will start the investigations,
discovering what is the function of the protein
encoded from AFF2 gen, and thus knowing
the pathological mechanism of autism
spectrum disorder, for do it´s post treatment.

17. MEDICAL UTILITY
 Mycoplasma genitalium causes, in some cases
infertility in women; so, by treatment these
bacteries with antibiotics, it would reduce the
numbers of infertility, giving these families the
posibility to have children.
 Currently there are antibiotics that have a role
similar to the mechanism of action is to seek to
block this new enzyme, RNase R, the inhibition
of protein synthesis. The antibiotics that inhibit
30 S ribosomal subunit are macrolides,
tetracyclines, aminoglycosides glycylcyclines.
And those that inhibit the 50S subunit are
glincosamidas, chloramphenicol, quetolidos.

18. MEDICAL UTILITY
 The study of the enzymes that the bacteries
use for do the protein´s synthesis, is key to
search new targets for antibiotics, and thus
make a better control of bacterial diseases;
this finding made by the molecular biology will
help to medical act enormously .

19. BIBLIOGRAFY
 Mutations in Autism Susceptibility Gene Increase Risk in
Boys.
Published on July 11, 2012
 Unique Mechanism Identified in Bacteria as Potential
Target for Developing New Antibiotics.
Published on July 20, 2012
 Cooper Geoffrey M, Cooper´s Cell, 4. ed. Editorial
Marban, 2008. 310p.
 MARTINEZ SÁNCHEZ, Lina María. Biología molecular. 7.
ed. Medellín: UPB. Fac. de Medicina, 2012. 75p.

20. GRACIAS