Fig. 2

Identification of two novel mutations in LHX3. a Sequencing chromatogram indicating the homozygous wild type, heterozygous carrier and homozygous mutant forms. Homozygous c.437 G > T (p. Cys146Phe) mutation is identified in affected individual (II:2, family 1). b Homozygous c.466 C > T (p. Arg156Ter) mutation is identified in affected individuals (II:2 & II:4, family 2). Nucleotide and amino acid numbering correspond to NM_014564.3 for the cDNA and NP_055379.1 for the protein. Nucleotides were numbered using A of the ATG translation initiation codon as +1 nucleotide of the coding sequence. Mutations are highlighted (arrow). c Ribbon/Cartoon-presentation of zinc finger motif of the LHX3 consisting of α-helix (green) and β-sheets (brown). The Zn binding residues of LIM domains are highly conserved; cysteine at position 146 (yellow) is a zinc ligating residue, involved in binding with the zinc cation (brown). d The multiple-sequence alignment was generated with the Clustal Omega Multiple Sequence Alignment tool and depicts conservation of the crucial p. Cys146 residue during evolution. Asterisk (*) indicates positions which have a single, fully conserved residue. Colon (:) indicates conservation between groups of strongly similar properties - scoring > 0.5. e LHX3 mutations associated with combined pituitary hormone deficiency. Schematic representation of intron-exon structure of LHX3 gene, domain graph of the encoded protein (Uniprot identifier: Q9UBR4), and the genetic variants. Exons are designated as boxes 1–6 and introns are shown by thin lines. A full-length wild type LHX3 protein is shown, with its N-terminus and C-terminus. Alternative splicing generates two isoforms, LHX3a and LHX3b, which are 397 and 402 amino acids long respectively. The isoforms differ only in the amino-terminal domains. Other known functional domains are following: LIM domains (LIM); homeodomain (HD), and carboxyl trans-activation domain (LSD). Novel variants identified in our study are boxed in red alongside previously reported variants in HGMD database [28]. The mutations are grouped according to canonical classes and further identified by their amino acid changes