Two Novel Mutations of the TSH-{beta} Subunit Gene Underlying Congenital Central Hypothyroidism Undetectable in Neonatal TSH Screening. (Epub ahead of print)

BAQUEDANO,MS ;; CIACCIO, M;; DUJOVNE N,; HERZOVICH V,; LONGUEIRA BACHELOR Y; WARMAN DM,; RIVAROLA MA,; BELGOROSKY, A

JOURNAL OF CLINICAL ENDOCRINOLOGY AND METABOLISM

ENDOCRINE SOC

Lugar: Chevy Chase, U.S.A.; Año: 2010 vol. 95 p. 1 - 1

0021-972X

Context: Patients with TSH-Betha subunit defects and congenital hypothyroidism are missed by TSHbased neonatal screening. neonatal screening. Patients with TSH-Betha subunit defects and congenital hypothyroidism are missed by TSHbased neonatal screening. Objective: Our objective was to report the molecular consequences of a novel splice-junction mutation and a novel missense mutation in the TSH-Betha subunit gene found in two patients with congenital central hypothyroidism and conventional treatment-resistant anemia. congenital central hypothyroidism and conventional treatment-resistant anemia. mutation and a novel missense mutation in the TSH-Betha subunit gene found in two patients with congenital central hypothyroidism and conventional treatment-resistant anemia. congenital central hypothyroidism and conventional treatment-resistant anemia. Our objective was to report the molecular consequences of a novel splice-junction mutation and a novel missense mutation in the TSH-Betha subunit gene found in two patients with congenital central hypothyroidism and conventional treatment-resistant anemia. congenital central hypothyroidism and conventional treatment-resistant anemia. Betha subunit gene found in two patients with congenital central hypothyroidism and conventional treatment-resistant anemia. Results: Patient 1 had a homozygous G to A nucleotide change at the 5' donor splice site of exon/intron 2. This resulted in a silent change at codon 34 of the mature protein. In vitro splicing assaysshowedthat themutantminigene dramatically affectedpre-mRNAprocessing, causing exon 2 to be completely skipped. The putative product from anewout-of-frame translational start point in exon 3 is expected to yield a nonsense 25-amino-acid peptide. In patient 2, sequence analysis revealed acompoundheterozygosis for the already reported 313delT (C105Vfs114X) mutation and for a second novel mutation in exon 3, substituting G for A at cDNA nucleotide position 323, resulting in a C88Y change. This cysteine residue is conserved among all dimeric pituitary and placental glycoprotein hormone-Betha subunits. Data from in silico analysis confirmed that the C88Y mutation would affect subunit conformation. Indeed, two different bioinformatics approaches, PolyPhen and SIFT analysis, predicted C88Y to be a damaging substitution. mutation would affect subunit conformation. Indeed, two different bioinformatics approaches, PolyPhen and SIFT analysis, predicted C88Y to be a damaging substitution. assaysshowedthat themutantminigene dramatically affectedpre-mRNAprocessing, causing exon 2 to be completely skipped. The putative product from anewout-of-frame translational start point in exon 3 is expected to yield a nonsense 25-amino-acid peptide. In patient 2, sequence analysis revealed acompoundheterozygosis for the already reported 313delT (C105Vfs114X) mutation and for a second novel mutation in exon 3, substituting G for A at cDNA nucleotide position 323, resulting in a C88Y change. This cysteine residue is conserved among all dimeric pituitary and placental glycoprotein hormone-Betha subunits. Data from in silico analysis confirmed that the C88Y mutation would affect subunit conformation. Indeed, two different bioinformatics approaches, PolyPhen and SIFT analysis, predicted C88Y to be a damaging substitution. mutation would affect subunit conformation. Indeed, two different bioinformatics approaches, PolyPhen and SIFT analysis, predicted C88Y to be a damaging substitution. exon/intron 2. This resulted in a silent change at codon 34 of the mature protein. In vitro splicing assaysshowedthat themutantminigene dramatically affectedpre-mRNAprocessing, causing exon 2 to be completely skipped. The putative product from anewout-of-frame translational start point in exon 3 is expected to yield a nonsense 25-amino-acid peptide. In patient 2, sequence analysis revealed acompoundheterozygosis for the already reported 313delT (C105Vfs114X) mutation and for a second novel mutation in exon 3, substituting G for A at cDNA nucleotide position 323, resulting in a C88Y change. This cysteine residue is conserved among all dimeric pituitary and placental glycoprotein hormone-Betha subunits. Data from in silico analysis confirmed that the C88Y mutation would affect subunit conformation. Indeed, two different bioinformatics approaches, PolyPhen and SIFT analysis, predicted C88Y to be a damaging substitution. mutation would affect subunit conformation. Indeed, two different bioinformatics approaches, PolyPhen and SIFT analysis, predicted C88Y to be a damaging substitution. assaysshowedthat themutantminigene dramatically affectedpre-mRNAprocessing, causing exon 2 to be completely skipped. The putative product from anewout-of-frame translational start point in exon 3 is expected to yield a nonsense 25-amino-acid peptide. In patient 2, sequence analysis revealed acompoundheterozygosis for the already reported 313delT (C105Vfs114X) mutation and for a second novel mutation in exon 3, substituting G for A at cDNA nucleotide position 323, resulting in a C88Y change. This cysteine residue is conserved among all dimeric pituitary and placental glycoprotein hormone-Betha subunits. Data from in silico analysis confirmed that the C88Y mutation would affect subunit conformation. Indeed, two different bioinformatics approaches, PolyPhen and SIFT analysis, predicted C88Y to be a damaging substitution. mutation would affect subunit conformation. Indeed, two different bioinformatics approaches, PolyPhen and SIFT analysis, predicted C88Y to be a damaging substitution. Patient 1 had a homozygous G to A nucleotide change at the 5' donor splice site of exon/intron 2. This resulted in a silent change at codon 34 of the mature protein. In vitro splicing assaysshowedthat themutantminigene dramatically affectedpre-mRNAprocessing, causingexon 2 to be completely skipped. The putative product from anewout-of-frame translational start point in exon 3 is expected to yield a nonsense 25-amino-acid peptide. In patient 2, sequence analysis revealed acompoundheterozygosis for the already reported 313delT (C105Vfs114X) mutation and for a second novel mutation in exon 3, substituting G for A at cDNA nucleotide position 323, resulting in a C88Y change. This cysteine residue is conserved among all dimeric pituitary and placental glycoprotein hormone-
subunits. Data from in silico analysis confirmed that the C88Y mutation would affect subunit conformation. Indeed, two different bioinformatics approaches, PolyPhen and SIFT analysis, predicted C88Y to be a damaging substitution. mutation would affect subunit conformation. Indeed, two different bioinformatics approaches, PolyPhen and SIFT analysis, predicted C88Y to be a damaging substitution. assaysshowedthat themutantminigene dramatically affectedpre-mRNAprocessing, causingexon 2 to be completely skipped. The putative product from anewout-of-frame translational start point in exon 3 is expected to yield a nonsense 25-amino-acid peptide. In patient 2, sequence analysis revealed acompoundheterozygosis for the already reported 313delT (C105Vfs114X) mutation and for a second novel mutation in exon 3, substituting G for A at cDNA nucleotide position 323, resulting in a C88Y change. This cysteine residue is conserved among all dimeric pituitary and placental glycoprotein hormone-
subunits. Data from in silico analysis confirmed that the C88Y mutation would affect subunit conformation. Indeed, two different bioinformatics approaches, PolyPhen and SIFT analysis, predicted C88Y to be a damaging substitution. mutation would affect subunit conformation. Indeed, two different bioinformatics approaches, PolyPhen and SIFT analysis, predicted C88Y to be a damaging substitution. In vitro splicing assaysshowedthat themutantminigene dramatically affectedpre-mRNAprocessing, causingexon 2 to be completely skipped. The putative product from anewout-of-frame translational start point in exon 3 is expected to yield a nonsense 25-amino-acid peptide. In patient 2, sequence analysis revealed acompoundheterozygosis for the already reported 313delT (C105Vfs114X) mutation and for a second novel mutation in exon 3, substituting G for A at cDNA nucleotide position 323, resulting in a C88Y change. This cysteine residue is conserved among all dimeric pituitary and placental glycoprotein hormone-
subunits. Data from in silico analysis confirmed that the C88Y mutation would affect subunit conformation. Indeed, two different bioinformatics approaches, PolyPhen and SIFT analysis, predicted C88Y to be a damaging substitution. mutation would affect subunit conformation. Indeed, two different bioinformatics approaches, PolyPhen and SIFT analysis, predicted C88Y to be a damaging substitution.
subunits. Data from in silico analysis confirmed that the C88Y mutation would affect subunit conformation. Indeed, two different bioinformatics approaches, PolyPhen and SIFT analysis, predicted C88Y to be a damaging substitution. Conclusions: In isolated TSH deficiency, the exact molecular diagnosis is mandatory for diagnosis of isolated pituitary deficiency, delineation of prognosis, and genetic counseling. Moreover, diagnosis of central hypothyroidism should be considered in the face of severe infant anemia of uncertain etiology. (J Clin Endocrinol Metab 95: 0000–0000, 2010) of isolated pituitary deficiency, delineation of prognosis, and genetic counseling. Moreover, diagnosis of central hypothyroidism should be considered in the face of severe infant anemia of uncertain etiology. (J Clin Endocrinol Metab 95: 0000–0000, 2010) In isolated TSH deficiency, the exact molecular diagnosis is mandatory for diagnosis of isolated pituitary deficiency, delineation of prognosis, and genetic counseling. Moreover, diagnosis of central hypothyroidism should be considered in the face of severe infant anemia of uncertain etiology. (J Clin Endocrinol Metab 95: 0000–0000, 2010)(J Clin Endocrinol Metab 95: 0000–0000, 2010)