An immunodeficiency disorder and one type of
SCIDs that is caused by an inborn error in the
metabolism of adenine. The accumulation of
Adenosine deaminase (ADA) adenine destroys both B and T lymphocytes.
deficiency
Increase in dATP is lymphotoxic
Defective purine salvage due to absent HGPRT,
which converts hypoxanthine to IMP and
guanine to GMP. Results in excess uric acid
production and de novo purine synthesis.
X-linked recessive
Findings: intellectual disability, selfmutilation,
Lesch-Nyhan syndrome aggression, hyperuricemia (orange "sand"
[sodium urate crystals] in diaper), gout,
dystonia.
Treatment: allopurinol or febuxostat
(2nd line)
Terms in this set (118)
1
, Caused by mutations in the BLM gene leading to
mutated DNA helicase protein formation
Bloom Syndrome Rare autosomal recessive disorder characterized by
short stature, predisposition to the development of
cancer and genomic instability
Nucleotide Excision Repair Defect
Defect prevents repair of pyrimidine dimers
Xeroderma pigmentosum (XP)
because of ultraviolet light exposure
Lynch Syndrome (Hereditary
Nonpolyposis Colorectal
Cancer)
Mismatch repair defect
Nonhomologous end joining defect
Defects in ATM gene = failure to repair DNA double
strand breaks cell cycle arrest.
Triad: cerebellar defects (Ataxia), spider
Angiomas (telangiectasia), IgA deficiency.
Ataxia Telangiectasia
Increased AFP.
Decreased IgA, IgG, and IgE.
Lymphopenia, cerebellar atrophy.
Fanconi anemia Nonhomologous end joining defect
Inherited lysosomal storage disorder
Defect in N-acetylglucosaminyl-1-phosphotransferase = failure of the Golgi
to phosphorylate mannose residues (ie, mannose-
6-phosphate) on glycoproteins = proteins are secreted extracellularly rather
I-Cell Disease (Inclusion cell than delivered to lysosomes.
disease/mucolipidosis type II)
Results in coarse facial features, clouded corneas, restricted joint movement,
and high plasma levels of lysosomal enzymes.
Often fatal in childhood
Autosomal Recessive disorder of Peroxisome
biogenesis due to mutated PEX genes
Zellweger syndrome
Results in hypotonia, seizures, hepatomegaly,
early death
2
, Autosomal recessive disorder of alpha oxidation (peroxisome) = phytanic acid
not metabolized to pristanic acid
Refsum disease Results in scaly skin, ataxia, cataracts/night blindness, shortening of 4th
toe, epiphyseal dysplasia
Tx: diet, plasmaphoresis
an X-linked disorder of Beta oxidation (peroxisome)
in which dysfunction of the adrenal cortex and
nervouse system demyelination are associated
with high levels of saturated verylong-chain fatty
acids (VLCFAs)
Results in VLCFAs buildup in adrenal
Adrenoleukodystrophy (ALD)
glands, white matter of the brain, testes
Progressive disease that can lead to adrenal
gland crisis, coma, death
Immotile cilia due to a dynein arm defect.
Results in male and female infertility due to
immotile sperm and dysfunctional fallopian tube
cilia, respectively; increased risk of ectopic pregnancy.
Kartagener syndrome (primary Can cause bronchiectasis, recurrent sinusitis,
ciliary dyskinesia) and situs inversus (eg, dextrocardia on CXR =
Defect in leftright Dynein can lead to
Dextrocardia)
3
SCIDs that is caused by an inborn error in the
metabolism of adenine. The accumulation of
Adenosine deaminase (ADA) adenine destroys both B and T lymphocytes.
deficiency
Increase in dATP is lymphotoxic
Defective purine salvage due to absent HGPRT,
which converts hypoxanthine to IMP and
guanine to GMP. Results in excess uric acid
production and de novo purine synthesis.
X-linked recessive
Findings: intellectual disability, selfmutilation,
Lesch-Nyhan syndrome aggression, hyperuricemia (orange "sand"
[sodium urate crystals] in diaper), gout,
dystonia.
Treatment: allopurinol or febuxostat
(2nd line)
Terms in this set (118)
1
, Caused by mutations in the BLM gene leading to
mutated DNA helicase protein formation
Bloom Syndrome Rare autosomal recessive disorder characterized by
short stature, predisposition to the development of
cancer and genomic instability
Nucleotide Excision Repair Defect
Defect prevents repair of pyrimidine dimers
Xeroderma pigmentosum (XP)
because of ultraviolet light exposure
Lynch Syndrome (Hereditary
Nonpolyposis Colorectal
Cancer)
Mismatch repair defect
Nonhomologous end joining defect
Defects in ATM gene = failure to repair DNA double
strand breaks cell cycle arrest.
Triad: cerebellar defects (Ataxia), spider
Angiomas (telangiectasia), IgA deficiency.
Ataxia Telangiectasia
Increased AFP.
Decreased IgA, IgG, and IgE.
Lymphopenia, cerebellar atrophy.
Fanconi anemia Nonhomologous end joining defect
Inherited lysosomal storage disorder
Defect in N-acetylglucosaminyl-1-phosphotransferase = failure of the Golgi
to phosphorylate mannose residues (ie, mannose-
6-phosphate) on glycoproteins = proteins are secreted extracellularly rather
I-Cell Disease (Inclusion cell than delivered to lysosomes.
disease/mucolipidosis type II)
Results in coarse facial features, clouded corneas, restricted joint movement,
and high plasma levels of lysosomal enzymes.
Often fatal in childhood
Autosomal Recessive disorder of Peroxisome
biogenesis due to mutated PEX genes
Zellweger syndrome
Results in hypotonia, seizures, hepatomegaly,
early death
2
, Autosomal recessive disorder of alpha oxidation (peroxisome) = phytanic acid
not metabolized to pristanic acid
Refsum disease Results in scaly skin, ataxia, cataracts/night blindness, shortening of 4th
toe, epiphyseal dysplasia
Tx: diet, plasmaphoresis
an X-linked disorder of Beta oxidation (peroxisome)
in which dysfunction of the adrenal cortex and
nervouse system demyelination are associated
with high levels of saturated verylong-chain fatty
acids (VLCFAs)
Results in VLCFAs buildup in adrenal
Adrenoleukodystrophy (ALD)
glands, white matter of the brain, testes
Progressive disease that can lead to adrenal
gland crisis, coma, death
Immotile cilia due to a dynein arm defect.
Results in male and female infertility due to
immotile sperm and dysfunctional fallopian tube
cilia, respectively; increased risk of ectopic pregnancy.
Kartagener syndrome (primary Can cause bronchiectasis, recurrent sinusitis,
ciliary dyskinesia) and situs inversus (eg, dextrocardia on CXR =
Defect in leftright Dynein can lead to
Dextrocardia)
3
