Skip to content
How It Works
Explore
Resources Ask a Question
Who It's For
Patients
Decode results, prep for appointments, weigh options.
Caregivers & advocates
Carry the research load for someone you love.
Providers & clinicians
Resources for patients in your practice.
Log In Ask a Question
PubMed This is a summary of 16 peer-reviewed journal articles Updated
Pediatric Endocrinology

Causes and Associated Risks: Why It Happens

At a Glance

Athyreosis (being born without a thyroid gland) is typically a chance event during early pregnancy, though it can sometimes involve genetic factors. Because the thyroid develops alongside other vital organs, your doctor may recommend heart or kidney ultrasounds to ensure your baby's overall health.

Understanding why your baby was born without a thyroid gland can help you feel more prepared for the road ahead. While it may feel natural to look for a single “cause,” athyreosis is usually the result of complex biological processes during early pregnancy. For most families, this is a sporadic event—meaning it happened by chance and is not a condition that is likely to repeat in future pregnancies [1][2].

The Genetic Map of Development

The thyroid gland begins to form very early in pregnancy. Several specialized genes act like “blueprints,” directing the thyroid to grow and move to its correct position in the neck [3][4]. If one of these blueprints is missing or has a small error, the gland may not develop at all.

Researchers have identified several key genes involved in this process:

  • PAX8: This gene helps “turn on” the production of thyroid hormones. Errors here can lead to a missing or very small thyroid [5][6].
  • NKX2-1 and NKX2-5: These genes are involved in the development of several organs. Mutations in NKX2-1 can sometimes be part of Brain-Lung-Thyroid Syndrome, where the child might also have mild breathing issues or muscle coordination challenges [7][8].
  • FOXE1: This gene is critical for the physical formation of the gland. Rare mutations in this gene can cause Bamforth-Lazarus Syndrome, which may include a cleft palate or unusual hair texture alongside athyreosis [9].

For the majority of children with athyreosis, these genetic changes are polygenic (involving multiple small genetic factors) or epigenetic (factors that influence how genes are used), rather than a simple inherited trait [10][11].

Note on Genetic Testing: Routine genetic testing is not typically required or recommended for every child with athyreosis. Treatment with thyroid hormone is the same regardless of the genetic cause. Your doctor will usually only suggest genetic testing if your baby shows physical signs of a specific syndrome (like a cleft palate or breathing issues).

Checking Other Body Systems

Because the thyroid develops at the same time as several other vital organs, children born with athyreosis have a slightly higher chance of having other “extra-thyroidal” (outside the thyroid) differences [12][13]. Most of these are minor, but your medical team will likely perform a few extra checks to be thorough.

The systems most commonly monitored include:

  • Cardiovascular (Heart): Heart-related differences are the most frequent associated finding [12][14]. Your doctor might order an echocardiogram (an ultrasound of the heart) to ensure everything is functioning correctly [15].
  • Urogenital (Kidneys and Bladder): Sometimes the kidneys develop differently. A simple renal ultrasound can check their shape and position [12][2].
  • Gastrointestinal and Musculoskeletal: While less common, doctors also look for minor differences in the digestive system or the way bones are formed [13].

A Proactive Approach

Hearing about “associated risks” can be scary, but remember that these extra screenings are a standard part of high-quality care. Finding and addressing any minor issues early ensures they don’t interfere with your child’s health. In most cases, these screenings come back normal, and the focus returns entirely to managing thyroid hormone levels through daily medication [16][15].

Common questions in this guide

Why was my baby born without a thyroid gland?
In most cases, athyreosis is a sporadic event, meaning it happens by chance during early pregnancy. Occasionally, it is caused by a missing or altered gene that acts as a blueprint for normal thyroid development.
Will my baby need genetic testing for athyreosis?
Routine genetic testing is generally not required because the daily thyroid medication treatment remains the same regardless of the genetic cause. Your doctor will typically only suggest testing if your baby shows physical signs of a specific genetic syndrome.
What other health screenings will my baby need?
Because the thyroid develops at the same time as other vital organs, your doctor may order an echocardiogram (heart ultrasound) or a renal ultrasound to ensure your baby's heart and kidneys formed and are functioning correctly.
What is Brain-Lung-Thyroid Syndrome?
This is a rare condition linked to a mutation in the NKX2-1 gene. Children with this syndrome are typically born without a thyroid and may also experience mild breathing issues or muscle coordination challenges.
Does a genetic mutation change how athyreosis is treated?
No, identifying a specific genetic mutation like PAX8 or FOXE1 does not change the core treatment plan. Your baby will still be treated with daily thyroid hormone medication to support their normal growth and development.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.What specific genetic tests, if any, do you recommend for my child?
  2. 2.Are there physical signs of conditions like Bamforth-Lazarus syndrome or Brain-Lung-Thyroid syndrome that you're looking for?
  3. 3.Should we schedule an appointment with a pediatric cardiologist for a screening echocardiogram?
  4. 4.Are there other screening tests, such as a kidney ultrasound, that we should consider?
  5. 5.If my child has a mutation in a gene like PAX8 or FOXE1, does that change their treatment plan?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (16)
  1. 1

    Sublingual thyroid ectopy: similarities and differences with Kallmann syndrome.

    Van Vliet G, Deladoëy J

    F1000prime reports 2015; (7()):20 doi:10.12703/P7-20.

    PMID: 25750738
  2. 2

    Whole-Exome Sequencing in Congenital Hypothyroidism Due to Thyroid Dysgenesis.

    Larrivée-Vanier S, Jean-Louis M, Magne F, et al.

    Thyroid : official journal of the American Thyroid Association 2022; (32(5)):486-495 doi:10.1089/thy.2021.0597.

    PMID: 35272499
  3. 3

    Next-generation sequencing of NKX2.1, FOXE1, PAX8, NKX2.5, and TSHR in 100 Chinese patients with congenital hypothyroidism and athyreosis.

    Wang F, Liu C, Jia X, et al.

    Clinica chimica acta; international journal of clinical chemistry 2017; (470()):36-41 doi:10.1016/j.cca.2017.04.020.

    PMID: 28455095
  4. 4

    Molecular investigation of TSHR gene in Bangladeshi congenital hypothyroid patients.

    Begum MN, Mahtarin R, Islam MT, et al.

    PloS one 2023; (18(8)):e0282553 doi:10.1371/journal.pone.0282553.

    PMID: 37561783
  5. 5

    Analysis of the PAX8 gene in 32 children with thyroid dysgenesis and functional characterization of a promoter variant.

    Perone D, Medeiros-Neto G, Nogueira CR, et al.

    Journal of pediatric endocrinology & metabolism : JPEM 2016; (29(2)):193-201.

    PMID: 26495924
  6. 6

    A Novel Pathogenic Variant in PAX8 Leads to Familial Congenital Hypothyroidism.

    França MM, Reeve L, Dumitrescu AM, et al.

    Thyroid : official journal of the American Thyroid Association 2022; (32(8)):1000-1002 doi:10.1089/thy.2022.0117.

    PMID: 35611983
  7. 7

    Combined mutations of NKX2-1 and surfactant protein C genes for refractory low oxyhemoglobin saturation and interstitial pneumonia: A case report.

    Gu R, Ye G, Zhou Y, Jiang Z

    Medicine 2020; (99(12)):e19650 doi:10.1097/MD.0000000000019650.

    PMID: 32195974
  8. 8

    [Brain-lung-thyroid syndrome in a newborn with deletion 14q12-q21.1].

    Villamil-Osorio M, Yunis LK, Quintero L, et al.

    Andes pediatrica : revista Chilena de pediatria 2021; (92(6)):930-936 doi:10.32641/andespediatr.v92i6.3287.

    PMID: 35506806
  9. 9

    A new FOXE1 homozygous frameshift variant expands the genotypic and phenotypic spectrum of Bamforth-Lazarus syndrome.

    Sarma AS, Banda L, Rao Vupputuri M, et al.

    European journal of medical genetics 2022; (65(10)):104591 doi:10.1016/j.ejmg.2022.104591.

    PMID: 35963604
  10. 10

    Mutation screening in the genes PAX-8, NKX2-5, TSH-R, HES-1 in cohort of 63 Brazilian children with thyroid dysgenesis.

    Cerqueira TLO, Ramos YR, Strappa GB, et al.

    Archives of endocrinology and metabolism 2018; (62(4)):466-471 doi:10.20945/2359-3997000000065.

    PMID: 30304112
  11. 11

    The mutation screening in candidate genes related to thyroid dysgenesis by targeted next-generation sequencing panel in the Chinese congenital hypothyroidism.

    Zhang RJ, Yang GL, Cheng F, et al.

    Clinical endocrinology 2022; (96(4)):617-626 doi:10.1111/cen.14577.

    PMID: 34374102
  12. 12

    A retrospective analysis of congenital anomalies in congenital hypothyroidism.

    Mazahir FA, Khadora MM

    Journal of pediatric endocrinology & metabolism : JPEM 2020; (33(9)):1147-1153 doi:10.1515/jpem-2020-0250.

    PMID: 32822318
  13. 13

    Incidence of primary congenital hypothyroidism and relationship between diagnostic categories and associated malformations.

    Tuli G, Munarin J, Tessaris D, et al.

    Endocrine 2021; (71(1)):122-129 doi:10.1007/s12020-020-02370-w.

    PMID: 32507964
  14. 14

    Hypothyroidism in Patients with Down Syndrome: Prevalence and Association with Congenital Heart Defects.

    Gorini F, Coi A, Pierini A, et al.

    Children (Basel, Switzerland) 2024; (11(5)) doi:10.3390/children11050513.

    PMID: 38790508
  15. 15

    Congenital Hypothyroidism.

    Al-Qahtani M

    The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians 2022; (35(19)):3761-3769 doi:10.1080/14767058.2020.1838480.

    PMID: 33115295
  16. 16

    An interpretation of "congenital hypothyroidism: a 2020-2021 consensus guidelines update-an ENDO-European Reference Network initiative endorsed by the European Society for Pediatric Endocrinology and the European Society for Endocrinology".

    Huang R, Zou FL, Li MJ, et al.

    Zhongguo dang dai er ke za zhi = Chinese journal of contemporary pediatrics 2021; (23(11)):1075-1079 doi:10.7499/j.issn.1008-8830.2106051.

    PMID: 34753537

This page provides educational information about the causes of athyreosis. It does not replace professional medical advice, so always discuss your child's specific diagnosis and screening needs with their pediatric endocrinologist.

Get notified when new evidence is published on Athyreosis.

We monitor PubMed for new peer-reviewed studies on this topic and email a short summary when something meaningful changes.