1. the importance of newborn screening
Congenital Adrenal Hyperplasia (CAH) and Congenital Hypothyroidism (CH)
the importance of newborn screening
Balázs Gellén MD. Ph.D.
Dept. of Pediatrics
University of Szeged

2. Congenital adrenal hyperplasia (CAH)
Refers to autosomal recessive diseases resulting from mutations of genes for enzymes mediating the steroidogenesis from cholesterol by the adrenal glands

3. Associated conditions
The symptoms of CAH vary depending upon the form of CAH and
the gender of the patient.
Symptoms can include:
Due to inadequate mineralocorticoids:
- vomiting due to salt-vasting leading to dehydration and death
Due to excess mineralocorticoids:
- hypertension (11 β-OH deficiency)
Due to excess androgens:
- ambiguous genitalia in some females, such that it can be
initially difficult to determine sex
- early pubic hair and rapid growth in childhood
- precocious puberty or absent or delayed puberty
- virilization (enlarged clitoris and shallow vagina), and/or
menstrual irregularity in adolescence
- infertility due to anovulation

4. Classification
Cortisol production begins in the second month of fetal life. Inefficient cortisol production results in rising levels of ACTH, which in turn induces overgrowth (hyperplasia) and overactivity of the androgen-producing cells of the adrenal cortex.
Synthesis of cortisol shares steps with synthesis of mineralocorticoids, androgens, and estrogens.
The resulting excessive or deficient production of these three classes of hormones produce the most important problems for people with CAH.

6. 11β-hydroxylase

7. ↓ ↑ 21OH-ase def. 90-95% P450c21 6p21.3 11βOH-ase def. 5% P450c 11β
Common medical term %
enzyme
locus
Substrate
Products
Mineralocorticoids
Androgens
21OH-ase def.
90-95%
P450c21
6p21.3
17OHprogesterone→ progesterone→
11deoxycortisol DOC ↓ ↑
11βOH-ase def. 5%
P450c 11β
8q21-22
11deoxycortisol→
DOC→
cortisol, corticosteron
3βHSD def.
Very rare
3βHSDII
1p13
pregnenolone →
17OH-pregnenolone →
DHEA →
progesterone
17OH-progesterone androstenedion
17αOH-ase def.
P450c17
10q24.3
pregnenolone → progesterone→
17OHpregnenolone →
17OHpregnenolone 17OHprogesterone
DHEA
20,22-desmolase def.
StarP450scc
8p q23-q24
transport of cholesterol cholesterol →
into mitochondrial
pregnenolone

8. 21-hydroxylase deficiency
The defective enzyme is P450c21 (cytochrome P450 oxidase ), commonly referred to as 21-hydroxylase (21-OH), encoded by the CYP21 gene.
CAH due to 21-OH deficiency accounts for about 95% of diagnosed cases of CAH.
The terms "salt-wasting CAH", and "simple virilizing CAH" usually refer to subtypes of this condition.
The incidence of salt wasting CAH is 1 in 15,000 children !!!

9. 21-hydroxylase CAH is inherited in an autosomal recessive fashion
CYP21 is paired with a nonfunctional pseudogene CYP21P

10. Penetrance
Variability and recombination of abnormal alleles of CYP21 and homologous region of CYP21P gene is introduced by the degree of enzyme inefficiency.
severe degrees produce changes in the fetus and problems in prenatal or perinatal life
milder degrees are usually associated with excessive or deficient sex hormone effects in childhood or adolescence
the mildest form of CAH interferes with ovulation and fertility in adults

11. salt-wasting CAH simple virilizing CAH non-classical CAH Type of 21OHD
Sex steroid effects
Other effects
Severe
salt-wasting CAH
The most common cause of ambigous genitalia due to prenatal virilization of genetically female (XX) infants.
Salt-wasting crisis - life-threatening vomiting and dehydration occurring within the first few weeks of life.
17OHP ↑ ↑ (30 ng/ml <)
Aldosterone ↓ Cortisol ↓
Moderate
simple virilizing CAH
Causing virilization of prepubertal children.
Cortisol ↓
Aldosterone normal
Milder form
non-classical CAH
(„late onset”)
Causing androgen effects and infertility in adolescent and adult women.
Cortisol normal

12. Newborn screening 1.
Conditions justifying newborn screening for any disorder include
(1) a simple test with an acceptable sensitivity and specificity,
(2) a dire and severe consequence if not diagnosed early,
(3) an effective treatment if diagnosed,
(4) a frequency in the population high enough to justify the expense.

13. Newborn screening 2.
In the last decade more countries are adopting newborn screening for salt-wasting CAH due to 21-OH deficiency, which can leads to death in the first month of life if not recognized.

14. Newborn screening 3.
Currently, in over 40 countries, every child born is screened for CAH at birth. This test will detect elevated levels of 17-hydroxy-progesterone (17-OHP).
Detecting high levels of 17-OHP enables early detection of CAH.
Newborns detected early enough can be placed on medication and live a relatively normal life.

15. Newborn screening 4.
The salt-wasting form of CAH is potentially fatal within a month if untreated.
Steroid replacement is a simple, effective treatment.
However, while the 17OHP level is easy to measure and sensitive (rarely missing real cases!!), the test has a poorer specificity.
It’s a higher rate of false positives than the screening tests for many other congenital metabolic diseases.

16. Newborn screening 5.
When a positive result is detected, the infant must be referred to a pediatric endocrinologist to confirm or disprove the diagnosis.
Since most infants with salt-wasting CAH become critically ill by 2 weeks of age, the evaluation must be done rapidly despite the high false positive rate.

17. The main future directions and discussions in development of CAH treatment:
debate over the value of genital reconstructive surgery and changing standards
debate over sex assignment of severely virilized XX infants
new treatments to improve height outcomes
newborn screening programs to detect CAH at birth
increasing attempts to treat CAH before birth

18. Basic guidelines of treatment of 21OHD:
supplying glucocorticoid to reduce hyperplasia and overproduction of androgens
providing replacement mineralocorticoid and extra salt if the person is deficient
additional treatments to optimize growth by delaying puberty or delaying bone maturation
genital reconstructive surgery if necessary
psychotherapy

21. Emergency Medical Information Card
CAH Passport
Emergency Medical Information Card
Name:
Date of Birth:
Address:
Parental phone number:
Doctor’s phone number:
Dg.:Congenital adrenal hyperplasia (21OHD)
Salt-wasting form/Simple virilising form
Hospital responsible for the care of patient
CAH is a special form of adrenal insufficiency.
The patient needs continuous STEROID
replacement therapy.
Maintenance dose:
Increase to two to three times regular dosage during
periods of intercurrent illness or other periods of stress.
IN EMERGENCY:
(severe stress or trauma, adrenal crisis)
GIVE Hydrocortisone* intravenously/intramuscularly
3-6 mg/kg or mg/m2 as a first aid before
transporting the patient to a hospital.
* Inj. Hydro-Adreson F
Aquosum, Inj. Solu-Cortef, Solu -Medrol
For the emergency room physician:
In the situation of adrenal crisis the patient will need
1.) Immediate IV normal saline with 5 % glucose
20 ml/kg in one hour followed by continuous and
appropriate IV fluid replacement in children,
a liter of normal saline with 5 % glucose in one-
two hours in adults followed by continuous and
appropriate IV fluid replacement and
2.) Solu-Cortef, or Hydro-Adreson F Aquosum
IV bolus injection:
younger than 3 years: 25 mg,
3-10 years: 50 mg,
in adolescents and adults: 100 mg.
Thereafter during the time of acute crisis, administer
for infants Solu-Cortef mg/day by IV drip or 4
divided doseses IM or IV, for young children 50-60
mg/day by continuous IV drip or 4 divided doseses IM
or IV, and for adolescents and adults 100 mg/day by
continuous IV drip or 4 divided doseses IM or IV.

22. „thyreos = shield”
(Thomas Wharton
1656 London)
thyroid hormons: thyroxin ,trijodthyronin
- iodine content dipeptid hormons
Key factor in:
- growing
- metabolism
- development of cardiovascular system
- development of central nervous system

23. Thyroid stimulating hormone (TSH)
TSH is a noncovalently linked glycoprotein heterodimer and is part of a family of pituitary hormones containing a common alpha subunit and a unique beta subunit that confers specificity.

24. TSHR
The thyroid-stimulating hormone receptor is a receptor (and associated protein) that responds to thyroid-stimulating hormone, and stimulates the production of thyroxine (T4) and triiodothyronine (T3). The TSH receptor is a member of the G protein-coupled receptor superfamily.
It is primarily found on the surface of the thyroid epithelial cells.

25. Paired box gene 8 - PAX8 - a member of the paired box (PAX) family
This gene encoded a transcription factor protein. This nuclear protein is involved in thyroid follicular cell development and expression of thyroid-specific genes.
Mutations in this gene have been associated with thyroid dysgenesis, thyroid follicular carcinomas and atypical follicular thyroid adenomas.

26. Congenital hypothyroidism (CH) is a condition of thyroid hormone deficiency present at birth.
Approximately 1 in 3000 newborn infants has a severe deficiency of thyroid function, while even more have mild or partial degrees.
If untreated for several months after birth, severe CH can lead to growth failure and permanent mental retardation.
Treatment consists of a daily dose of thyroid hormone (thyroxine) by mouth.
Because the treatment is simple, effective, and inexpensive, nearly all of the developed world practices newborn screening to detect and treat CH in the first 7-14 days of life.

27. ETIOLOGY of CH (1.)
In the past the most common cause WAS iodine deficiency, but in most of the developed world areas of adequate environmental iodine and iodine supply reduce this problem.
Defect of development of the thyroid gland itself, resulting in an absent (agenesia) or underdeveloped (hypoplastic) gland. A hypoplastic gland may develop higher in the neck or even in the back of the tongue or other region (ectopic).
result from genetic defects, and some are "sporadic," with no identifiable cause.
CH detected by screening may be transient
most common cause of this is the presence of maternal antibodies which temporarily impair or inhibits thyroid function for some week.

28. ETIOLOGY of CH (2.)
85% thyreoid gland dysgenesis organification def.
agenesia, hypoplasia, ectopia
10% dyshormongenesis - defects of thyroxine or triiodothyronine synthesis within a structurally normal gland - nongoitrous CH
TRH,TSH ,TSHR def.,TSH resistance, iodine trapping and transport def., thyroglobulin def., deiodinase, peroxydase def., G-protein def.
2% transcription factor gene mutation
TTF1, TTF2, PAX8
3% others – maternal radio-iodine therapy during pregnancy etc.

29. DIAGNOSTIC EVALUATION - Newborn screening 1.
Nearly all cases of congenital hypothyroidism
can be detected by the newborn screening
program.
- These are based on measurement of TSH (and/or in some countries free thyroxine - fT4) on the second or third day of life.

30. DIAGNOSTIC EVALUATION - Newborn screening 2.
If the TSH is high (or the fT4 low), the screening
labor must calls infant's doctor (or GP), parents and
regional pediatric endocrinologist and the baby must be
referred to a pediatric endocrine center to confirm the
diagnosis and initiate treatment.
Often a technetium (Tc-99m pertechnetate) thyroid
scan is performed at diagnosis to detect a structurally
abnormal gland (because it has no therapeutic
consequences, usually we recommend it later age in
Hungary).

31. Newborn screening 3. In Hungary: - Incidency of CH: 1:3000
- Screening program from 1984: Guthrie-test
(+ PKU, galactosaemia, biotinidase def. - MTS)
- measurement of TSH must be on the 2nd or 3rd day
of life – DRIED BLOOD SPOT
If TSH > 30 μU/ml
the infant must be transported to the regional pediatric
endocrinology and screening center to confirm the
diagnosis and initiate treatment.
If TSH = μU/ml – test must be repeated
immidiately

32. Symptoms 1.
Infants born with CH may show no effects, or may display mild effects that often go unrecognized as a problem (!)
If fetal deficiency was severe because of complete absence of the gland, physical features may include more characteristic signs

33. Classic signs: excessive sleeping, reduced
interest in nursing, bad appetite, poor muscle
tone, low or hoarse cry, infrequent bowel
movements, constipation, exaggerated jaundice,
low bodytemperature, dry skin, larger anterior
fontanel, persistence of a posterior fontanel,
umbilical hernia, large tongue (macroglossia),
lethargia, wide nasal sella, oedema, bradycardia
and sometimes - goiter .

34. Symptoms 2.
In the era before newborn screening, less
than half of cases of severe hypothyroidism
were recognized in the first month of life (!)
These infants would grow poorly and be
delayed in their development.
By several years of age, they would display
the recognizable facial and body
features of cretinism with
severe mental and physical
retardation, with an IQ below
80 in the majority.

35. Treatment 1.
The goal of newborn screening programs is to detect and start treatment within the first 1–2 weeks of life.
Treatment consists of a daily dose of thyroxine, available as a small tablet. The generic name is levothyroxine, and several brands are available.
The tablet is crushed and given to the infant with a small amount of water or milk.

36. Treatmnet 2.
The most commonly recommended dose about μg/kg daily, typically 50 (or 37,5) μg.
Within a few weeks, the freeT4 and TSH levels are rechecked to confirm that they are being normalized by treatment.
As the child grows up, these levels are checked regularly to maintain the right dose.

37. Treatment guideline: Dosage: 12-15 μg/kg/day LT4 ≈ 50μg = 1tbl/day LT4
(Letrox, Euthyrox, L-Thyroxin)
to maintain the right dose of LT4
based on clinical signs and regular
checked lab results of serumTSH,
freeT4 (and dried blood spotTSH)
Timepoint of regular checking:
1-3 months of age - monthly
3-12 months of age – 2-3 monthly
1-2 years of age – 4 monthly
2-3 years of age – 6 monthly
From 3 years of age monthly

38. Prognosis
Most children born with CH and correctly treated with thyroxine grow and develop normally in all respects, develop with normal intelligence.
In some cases, the CH patients as a population academic performance tends to be below that of siblings and may occur mild learning problems (due to bad compliance?, due to intrauterin hypothyreoid condition?)
Congenital hypothyroidism is the most common preventable cause of mental retardation.
Few treatments in the practice of medicine provide as large a benefit for as small an effort.

39. Other benefits of TSH-screening
The dried blood spot test forTSH is a
capabel method to screen and check not only
CH but all hypothyreoid patients.
The GP, parents, welfare nurse can take easily
the sample, and send it by post to the Endocrine
Center (between two outpatient clinic visits)
to follow the efficacy of treatment,
to maintain the right dose of LT4,
to check and improve compliance.

42. Hypothyreosis ● ● ● ● ● ● ● ● ● ● ●
LT4
rhGH ●