Bamforth-Lazarus syndrome
Definicija
Bamforth-Lazarus syndrome is a very rare syndrome of congenital hypothyroidism characterized by thyroid dysgenesis (in most cases athyreosis), cleft palate and spiky hair, with or without choanal atresia, and bifid epiglottis. Facial dysmorphism and porencephaly have been reported in isolated cases.
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Pun naziv
Bamforth-Lazarus syndrome
Kratki naziv
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Sinonimi
Bamforth syndromeAthyroidal hypothyroidism-spiky hair-cleft palate syndromeHypothyroidism-cleft palate syndrome
Orpha broj
Kategorija
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Naziv na stranom jeziku
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Prevalenca
NULL
Nasleđivanje
Autosomal recessive
Period početka bolesti
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ICD 10
OMIM
UMLS
GARD
MEDDRA
Tekstualni opis
Newborns present at birth with thyroid dysgenesis (in most cases athyreosis) leading to congenital hypothyroidism that manifests with lethargy, poor feeding, macroglossia, cold or mottled skin, persistent jaundice, and umbilical hernia. Neonatal hyperbilirubinemia is also common. All newborns with Bamforth- Lazarus syndrome have a cleft palate and spiky hair. Some may also present with choanal atresia and bifid epiglottis. Facial dysmorphism, consisting of microcephaly, hypertelorism, anteverted nares, narrow nasal bridge, low-set ears, small jaw and retrognathia, has been reported in one case. Porencephaly was also recently described in one case.
Etiologija
Bamforth-Lazarus syndrome is due to homozygous loss-of-function missense mutations located within the forkhead domain of the FOXE1 gene (9q22), encoding thyroid transcription factor 2 (TTF-2). TTF-2 is expressed in the thyroid gland (as well as elsewhere like the tongue, epiglottis and palate) and is thought to play a crucial role in thyroid morphogenesis. Cases reported so far have all been due to homozygous loss-of-function mutations apart from one case described recently with a novel FOXE1 homozygous mutation causing increased thyroid gene expression.
Prognoza
bolest_prognoza
Diferencijalna dijagnoza
Differential diagnoses include other forms of syndromic hypothyroidism such as Johanson-Blizzard syndrome (see these terms).
Tretman
Thyroid hormone replacement therapy is the standard treatment for those with Bamforth-Lazarus syndrome and should be started as soon as possible. The dosage of synthetic thyroxine (T4) necessary depends on the patient's age, weight and any other medical conditions. Regular follow up is recommended to monitor any fluctuation in TSH levels and treatment is lifelong. In neonates born with hyperbilirubinemia, phototherapy is often effective. Surgical procedures for cleft palate (maxillo-facial reconstruction and plastic surgery) and choanal atresia (surgery to reopen the nasal passages) should be discussed in a specialized health center. Speech therapy may also be required.
Dijagnostičke metode
Diagnosis is based on clinical findings of congenital hypothyroidism with cleft palate and spiky hair along with findings of thyroid ultrasonography (USG) and computed tomography examination. Thyroid tissue is either completely absent or non-functional. Serum thyroid stimulation hormone (TSH) levels should be measured (levels will be elevated on newborn screening filter paper test, as is seen in all cases of athyreosis) to determine necessary treatment dosage. Molecular genetic testing can identify a mutation in the FOXE1 gene, confirming diagnosis.
Antenatalna dijagnoza
Prenatal diagnosis is not performed.
Epidemiologija
Only 8 patients from 6 families have been reported to date.
Genetsko savetovanje
The disease is inherited autosomal recessively and genetic counseling is possible. Most of the patients reported to date came from consanguineous parents, both being heterozygous for the genetic mutation.
Terapija
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Klinička istraživanja
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