Page 220 - Concise Pathology for Exam Preparation ( PDFDrive )

8 Genetic and Paediatric Disorders 205

TABLE 8.2. Principal groups of glycogenoses

Clinicopathological Morphological
category Specific type Enzyme deficiency changes Clinical features
Hepatic type Hepatorenal (von Glucose-6- Hepato and renomeg- Failure to thrive,
Gierke disease) phosphatase aly: intracytoplas- stunted growth,
mic accumulation of hypoglycaemia,
glycogen hyperuricaemia,
hyperlipidaemia
Myopathic type McArdle disease Muscle phosphorylase Skeletal muscle: accu- • Painful cramps,
(type V) mulation of glyco- myoglobinuria
gen in the sarcolem- • No increase in
mal location lactic acid with
exercise
Miscellaneous • Generalized gly- Lysosomal glucosi- Mild hepatomegaly, • Massive cardio-
cogenosis dase (acid maltase) cardiomegaly, de- megaly, muscle
• Pompe disease posits in skeletal hypotonia, cardio-
(type II) muscle respiratory failure
within 2 years
• Milder adult form
with only skeletal
muscle involve-
ment, presents
with chronic
myopathy

(e) Diethylstilbestrol (DES): DES causes abnormalities in Mullerian structures,
eg, vaginal adenosis and is a precursor of clear cell adenocarcinoma of cervix.
(f) Thalidomide: It is associated with limb abnormalities: amelia (absent limbs) and
phocomelia (seal-like limbs).
(g) Phenytoin: Consumed during pregnancy, phenytoin is associated with hypoplasia of
the distal phalanges, CNS abnormalities and cleft lip/palate.
(h) Diabetes mellitus: Children of diabetic mothers may manifest with increased birth-
weight (macrosomia), open neural tube defects, cleft lip/palate, respiratory distress
syndrome and transposition of great vessels.
2. Infectious teratogens
(a) Cytomegalovirus (CMV)
(i) Most common in utero viral infection.
(ii) Primarily transplacental transmission.
(iii) May manifest with hearing loss, periventricular calcification, neonatal cholesta-
sis, anaemia, thrombocytopenia, chorioretinitis (blindness) and microcephaly.
(iv) Virus can be isolated from urine, saliva, blood and tissue. Histopathology
reveals basophilic intranuclear inclusions labelled ‘owl’s eye appearance’.
(b) Rubella
(i) Primarily transplacental transmission.
(ii) Manifests with nerve deafness (most common defect), congenital heart disease
(patent ductus arteriosus), cataract and mental retardation.
(iii) Positive serologic test (TORCH) indicates disease.
(c) Toxoplasmosis
(i) Maternal infection secondary to exposure to cats.
(ii) Primarily transplacental transmission.
(iii) Manifests with chorioretinitis (blindness), periventricular calcifications,
microcephaly, mental retardation and neonatal cholestasis.
(iv) Positive serologic test (TORCH) indicates disease.
(d) Herpes simplex
(i) Primarily perinatal transmission while passing through birth canal with active
shedding of herpes genitalis (HSV-2 baby should be delivered by caesarean
section if viral shedding present).

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