81- Are congenital malformations common in newborns with congenital
hypothyroidism?
There is a four-fold higher prevalence of congenital malformations in newborns
with congenital hypothyroidism as compared to general population (8.4 % vs.
2 %). Congenital cardiac malformations are most common, followed by
malformations of nervous system and eyes and cleft lip/palate. The most
common congenital cardiac malformation is ostium secundum atrial septal
defect, followed by tetralogy of Fallot and pulmonary stenosis. - What are the radiological manifestations of congenital hypothyroidism?
Thyroid hormones play an important role in epiphyseal growth and development.
Thyroid hormone defi ciency during intrauterine period may result in absent
distal femoral and upper tibial epiphyses (in a term newborn) and wide posterior
fontanelle. Epiphyseal dysgenesis, short long bones, anterior beaking of 12 th
thoracic, fi rst and second lumbar vertebra, enlarged sella, and delayed bone age
are other manifestations of untreated congenital hypothyroidism in a child.- What is Kocher – Debre – Semelaigne syndrome?
Kocher–Debre–Semelaigne syndrome refers to pseudohypertrophy of calf
muscles as a result of long-standing untreated congenital/juvenile hypothyroid-
ism. Pseudohypertrophy is a result of accumulation of glycogen, glycosamino-
glycans, and connective tissue in the muscle as a result of hypothyroidism. The
level of creatine phosphokinase is mildly elevated and electromyogram shows
a myopathic pattern. The counterpart of Kocher–Debre–Semelaigne syndrome
in adults is Hoffman’s syndrome. Both these disorders are reversible with
thyroxine therapy (Fig. 3.5 ).a bFig. 3.5 ( a ) Myxedematous features in a girl with long-standing untreated primary hypothyroid-
ism. ( b ) Pseudohypertrophy of the calf muscles in the same patient
3 Thyroid Disorders in Children