Brief Answer:
congenital hypothyroidism-needs supplementation of l thyroxin

Detailed Answer:
Hello

Thanks for asking on this platform

I have seen the report of thyroid scan and it shows dysgenesis of thyroid gland with only a small ectopic thyroid tissue at base of tongue that too is functionally inadequate.
Dysgenesis of thyroid gland is the most common cause of congenital hypothyroidism and it needs long term supplementation of L thyroxine.
When diagnosed early recovery and prognosis is good.
In 10 percent cases there may be associated congenital heart defect or hearing defect.
I would suggest you to consult your physician for early treatment and also to rule out other associated anomaly if any.

I hope this helps.
I shall be glad to help you out in case you have any more doubt.
Wishing for your baby's good health.
Regards

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Brief Answer:
Echo and BERA test can be done

Detailed Answer:
Thanks for follow up

Now a days neonatal screening for hypothyroidism is done at most of the places to detect it early.
As early the treatment gets started outcome is better.Even 4.5 months of age is not much delayed as growth of brain occurs in first two years of life and some of thyroid hormone comes from mother to the baby.
So I won't get overly worried even if treatment starts at this age.
I said in 10% of cases of congenital hypothyroidism there can be associated cardiac or hearing abnormality.Cardiac abnormality can be detected by clinical examination.So although echo is the modality of choice,it may be deferred if there is no clinical finding.But detecting hearing abnormality by clinical examination is difficult.So I would suggest you to go for BERA test for hearing assessment.

Regards

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