Latest audiograms of the three patients shown in <b>Figs. 1</b> and <b>2</b>.

<p>Patients 15 and 29 have become cochlear implant users. The HL threshold of patient 28 has still not changed.</p

Heteroplasmy level of the m.3243A>G mutation in examined tissues.

<p>Above: the scores of patients with multi-symptomatic presentation (subgroup I). Below: the scores of patients with isolated hearing loss and asymptomatic carriers (subgroups II and III together).</p

Heteroplasmy levels (% of total tissue DNA) of m.3243A>G mutation in mtDNA samples isolated from: urinary sediment, hair follicles, buccal mucosa, nails and blood (put in order of heteroplasmy intensity).

<p>F = female, M = male, yrs = years, NA = not applicable.</p><p>The subgroups of patients: I – multi-organ presentation, II - isolated hearing loss and III - asymptomatic are presented separately.</p

Comparison of clinical status among all groups of patients (I, II and III) carrying m.3423A>G mutation: I = Multi-symptomatic subgroup, II = Isolated HL subgroup, III = Asymptomatic subgroup.

*<p>2 patients had only part 2 assessed.</p>**<p>11/12 patients were assessed.</p>***<p>probably false positive related to high score for quality of life (part 1) of two patients.</p><p>HL = hearing loss; NMDAS = Newcastle Mitochondrial Disease Adult Scale; MRS = magnetic resonance spectroscopy,</p><p>LA = lactic acidosis, MGCA = 3-methylglutaconic aciduria, MRI = magnetic resonance imaging; NA = not applicable.</p><p>GC-MS = Gas Chromatography–Mass Spectroscopy.</p><p>Degree of HL: mild HL<40 dB; moderate 41–70 dB; severe 71–90 dB; profound >91 dB.</p

Characteristics of the patients carrying the m.3243A>G mutation patients 1–17 with multi-organ presentation (subgroup I), patients 18–29 with isolated hearing loss (subgroup II), and asymptomatic carriers 30–34 (subgroup III).

<p>Probands are shown in bold.</p><p>GC-MS = gas chromatography–mass spectroscopy; NMDAS = Newcastle Mitochondrial Disease Adult Scale; MGCA = 3-methylglutaconic aciduria; LA = lactic aciduria; HL = hearing loss; NP = not performed; NA = normal value; QoL = quality of life; CI = cochlear implant user; IMGP = increased mineralisation of globus pallidus; MCA = minimal cerebellar atrophy; MRS = magnetic resonance spectroscopy; MRS score: 0 = negative LA, 1 = uncertain LA, 2 = positive LA, 3 = strong LA.</p><p>C = cardiomyopathy; DM = diabetes mellitus; H = migraine; I = infertility; K = renal insufficiency; M = myopathy; N = peripheral neuropathy; RP = pigmentary degeneration of retina; S = stroke-like episodes; SS = short stature.</p><p>No HL = normal hearing.</p>*<p>Stress = hearing deterioration following stressful event; Aminogly = hearing deterioration following aminoglycoside administration; Noise = hearing deterioration following noise exposure; Pancreatitis = hearing deterioration following acute pancreatitis; Pregnancy = hearing deterioration after pregnancy.</p

The sequences of the primers M_F and M_R.

<p>The sequences of the primers M_F and M_R.</p

Identification of <i>POU3F4</i> mutations.

<p>Family pedigrees (left panel) accompanied by chromatograms from <i>POU3F4</i> Sanger sequencing (middle panel) and Integrative Genomics Viewer (IGV) views (right panel) are shown. Circles represent females and squares represent males. The filled symbols indicate affected individuals and dots inside symbols indicate female carriers. Probands are marked with arrows. <i>POU3F4</i> mutations (novel in red, known in black) identified in the respective families (A-H) are given below the symbols.</p

Clinical characterization of patients harboring <i>POU3F4</i> mutations.

<p>Clinical characterization of patients harboring <i>POU3F4</i> mutations.</p

Scheme of the screening strategy.

<p>Novel mutations are bolded and marked in red. ¹ tested previously for all <i>GJB2</i> mutations, <i>GJB6</i> deletions (del(GJB6-D13S1830) and del(GJB6-D13S1853)), m.A1555G and m.A3243G ²HL patients previously tested for 6 <i>GJB2</i> mutations (c.-23+1G>A, c.35delG, c.167delT, c.313_326del, c.334_335delAA, c.358_360delGAG), <i>GJB6</i> del(GJB6-D13S1830) and m.1555A>G, m.3243A>G) ³selected from clinical database with the following keywords: abundant fluid leak, liquorrhoea, gusher, perilymphatic leak, IP3 malformation</p

MOESM1 of Novel neuro-audiological findings and further evidence for TWNK involvement in Perrault syndrome

Additional file 1: Figure S1. Sequence-to-structure alignment between the human Twinkle protein (Hs) and the template (PDB code 1e0j). The numbers of residues that are not shown are specified in parentheses. Identical residues are highlighted in yellow. Locations of observed (for 1e0j) and predicted (for Hs) secondary structure elements are marked above and below the corresponding sequences. Helices are presented as blue cylinders, while beta strands as orange arrows