2009 Vienna - European Society of Human Genetics
2009 Vienna - European Society of Human Genetics
2009 Vienna - European Society of Human Genetics
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Molecular basis <strong>of</strong> Mendelian disorders<br />
P12.041<br />
the study <strong>of</strong> the CYP A gene mutations in children with<br />
congenital adrenal hyperplasia from Republic Bashkortostan<br />
(Russia)<br />
V. L. Akhmetova1 , Z. F. Ramova2 , O. A. Malievsky2 , E. K. Khusnutdinova1 ;<br />
1 2 Institute <strong>of</strong> Biochemistry and <strong>Genetics</strong>, Ufa, Russian Federation, Bashkir<br />
State Medical University, Ufa, Russian Federation.<br />
Congenital adrenal hyperplasia (CAH) is a group <strong>of</strong> autosomal recessive<br />
disorders <strong>of</strong> adrenal steroidgenesis in which 21-hydroxylase deficiency<br />
accounts for over 95% <strong>of</strong> cases.<br />
We studied 68 patients with CAH from 68 families. The patients were<br />
divided into 2 groups according to clinical findings: salt wasting (SW)<br />
(N=41) and simple virilizing (SV) (N=27). We screened CAH-patients<br />
for 11 the most common mutations in the CYP21A2 gene: large gene<br />
deletion or large gene conversion (delA2/LGC), G110del8nt, P30L,<br />
I2splice, I172N, V281L, Q318X, R356W, E6cluster, F306+1nt .<br />
Mutations <strong>of</strong> the CYP21A2 gene were revealed in 84.51% <strong>of</strong> the studied<br />
CAH-chromosomes. The mutations were distributed as follows: delA2/<br />
LGC (33.1%), R356W (19.72%), I2splice (13.38%), I172N (8.45%),<br />
Q318X (7.04%), P30L (1.41%) and V281L (1.41%). In 15.49% CAHchromosomes<br />
mutations were not identified. We found 8 patients who<br />
carried 3 mutations, two from which formed a cluster: Q318X+R356W<br />
(N=5), I172N+Q318X (N=2), I172N+R356W (N=1). This complex <strong>of</strong><br />
alleles probably resulted from large conversions or multiple mutations<br />
events.<br />
In patients with SW form the most frequent mutation was delA2/LGC<br />
(39.08%), while R356W, I2splice and Q318X were found with lower<br />
frequencies (25.29%, 16.09% and 10.35%, respectively). In patients<br />
with SV form the most common mutations were delA2/LGC (25%)<br />
identified only in compound heterozygous state and I172N (17.86%),<br />
followed by R356W (10.71%) and I2splice (8.93%). Thus, we have<br />
been able to detect the spectrum <strong>of</strong> diagnostic significant CYP21A2<br />
gene mutations typical for SW and for SV forms <strong>of</strong> CAH patients.<br />
P12.042<br />
mutation screening <strong>of</strong> cYP1B1 Gene in North indian congenital<br />
Glaucoma Patients<br />
M. Tanwar1 , T. Dada2 , R. Sihota2 , V. Gupta2 , R. Dada1 ;<br />
1 2 Deptt. <strong>of</strong> Anatomy, AllMS, New Delhi, India, Dr. R.P.Centre for Ophthalmic Sciences,<br />
AllMS, New Delhi, India.<br />
Primary congenital glaucoma is an inherited ocular congenital disorder<br />
that can result in permanent blindness. Its prevalence varies across<br />
ethnic communities, ranging from 1 in 10,000-20,000 in the western<br />
populations to 1 in 3300 in Southern India. Aim <strong>of</strong> this study was to<br />
investigate the predominant mutations in CYP1B1 gene in north-Indian<br />
PCG patients. Fifty PCG patients and 50 ethically matched controls<br />
without any ocular disease were enrolled in the study. CYP1B1<br />
gene was screened for six most prevalent mutations (Termination at<br />
223, Gly61Glu, Pro193Leu, Glu229Lys, Arg368His and Arg390Cys) by<br />
PCR-RFLP method. On PCR-RFLP analysis total 20/50(40%) showed<br />
either <strong>of</strong> these mutation. Ter@223 was found in 18%, R390C in 16%<br />
and R368H in 8% patients. On DNA sequencing R390C mutation was<br />
found to be R390H and three novel (L24R, F190L and G329D) mutations<br />
were identified. Because <strong>of</strong> Ter@223 mutation a functional null<br />
protein is produced. Arginine residues at 368 and 390 are highly conserved<br />
in cytochrome 450 proteins. These map to helix K, which is<br />
involved in proper protein folding and heme binding. E229 amino acid<br />
(aa) residue are also conserved in different cytochrome P450 proteins.<br />
E229K mutation can cause conformational changes in the protein. The<br />
most prevalent CYP1B1 mutation in our population is Ter@223 (18%)<br />
followed by R390H (16%) while from other studies from south India<br />
R368H was the most prevalent CYP1B1 mutation. Our data is different<br />
from southern population it may be because <strong>of</strong> genetic heterogeneity<br />
<strong>of</strong> the disease and different evolutionary history <strong>of</strong> both populations.<br />
P12.043<br />
Hypoplastic left heart syndrome: is it all in HAND?<br />
D. Barachetti 1 , D. Marchetti 1 , F. Seddio 2 , L. Boni 3 , A. R. Lincesso 1 , S. Villagra 3 ,<br />
A. Mendoza 3 , L. Pezzoli 1 , L. Galletti 2 , P. Ferrazzi 2 , M. Iascone 1 ;<br />
1 Genetica Molecolare - USSD Lab. Genetica Medica, Ospedali Riuniti, Bergamo,<br />
Italy, 2 Dipartimento Cardiovascolare, Ospedali Riuniti, Bergamo, Italy,<br />
3 Instituto Pediatrico del Corazon Hospital “12 de Octubre”, Madrid, Spain.<br />
Hypoplastic left heart syndrome (HLHS) consists <strong>of</strong> a heterogeneous<br />
group <strong>of</strong> cardiac malformations with various degrees <strong>of</strong> underdevelopment<br />
<strong>of</strong> the left heart-aorta complex. It is one <strong>of</strong> the most severe congenital<br />
heart diseases and it’s usually lethal during early infancy. Most<br />
hypotheses formulated to explain the pathogenesis <strong>of</strong> HLHS assume<br />
that there is a primary anatomic/genetic abnormality which results in<br />
low flow through the left heart and it is the diminished flow that ultimately<br />
leads to growth failure <strong>of</strong> the left sided structures. The molecular<br />
causes <strong>of</strong> HLHS are unclear. A recent report <strong>of</strong> mutations in basic<br />
helix-loop-helix (bHLH) transcription factor HAND1 found in hearts<br />
with HLHS has suggested that in hypoplastic human hearts HAND1<br />
function is impaired. Because <strong>of</strong> the pr<strong>of</strong>ound implication <strong>of</strong> this finding,<br />
we attempted to replicate it using peripheral blood samples from<br />
46 patients and 8 different cardiac samples obtained from 5 patients<br />
with HLHS who underwent cardiac surgery.<br />
Newborns and children (25% female) with HLHS undergo a complete<br />
evaluation to determine the type <strong>of</strong> defect and the potential presence<br />
<strong>of</strong> extracardiac defect. The mean age at surgical intervention was 8<br />
days old. We sequenced the entire HAND1 gene starting from genomic<br />
DNA extracted from peripheral blood lymphocytes and from cardiac<br />
samples. No evidence <strong>of</strong> germline or somatic mutations was found in<br />
this study.<br />
Germline and somatic mutations in HAND1 do not seem to be a frequent<br />
cause <strong>of</strong> abnormal cardiac development at basis <strong>of</strong> HLHS.<br />
This work is supported by Telethon grant GGP07235<br />
P12.044<br />
A chinese patient with congenital nephrotic syndrome <strong>of</strong> the<br />
Finnish type caused by compound heterozygous mutations in<br />
NPHS<br />
Y. P. Yuen 1 , W. K. Siu 2 , S. C. Lau 3 , A. Y. Chan 4 , C. W. Lam 5 ;<br />
1 Department <strong>of</strong> Pathology, Hong Kong, China, 2 Department <strong>of</strong> Obstetrics and<br />
Gynecology, Princess Margaret Hospital, Hong Kong, China, 3 Department <strong>of</strong><br />
Paediatrics & Adolescent Medicine, Princess Margaret Hospital, Hong Kong,<br />
China, 4 Department <strong>of</strong> Pathology, Princess Margaret Hospital, Hong Kong,<br />
China, 5 Department <strong>of</strong> Pathology, The University <strong>of</strong> Hong Kong, Hong Kong,<br />
China.<br />
Mutations in NPHS1 (OMIM no.256300), NPHS2 (OMIM no.600995),<br />
WT1 (OMIM no.194080 and 136680) and LAMB2 (OMIM no.609049)<br />
are known to account for the majority <strong>of</strong> early-onset hereditary nephrotic<br />
syndromes. Our patient was the first child <strong>of</strong> non-consanguineous<br />
Chinese parents. She was born prematurely at 34 weeks with<br />
a birth weight <strong>of</strong> 1.98 kg. The placenta weighed more than 53% <strong>of</strong><br />
the birth weight. She was noted to have facial puffiness, abdominal<br />
distension and pitting edema in her extremities on Day 13 after birth.<br />
Nephrotic syndrome was confirmed by laboratory investigations. The<br />
karyotype was 46,XX and no ocular abnormalities were noted. Left<br />
nephrectomy was performed when the patient was 4 months old for<br />
deteriorating symptoms in spite <strong>of</strong> daily albumin infusion and the use<br />
<strong>of</strong> indomethacin and ACEI. Ultrastructural examination <strong>of</strong> the removed<br />
kidney showed narrow slits and absence <strong>of</strong> slit diaphragm. The entire<br />
coding sequences and flanking introns in NPHS1, NPHS2 and<br />
WT1 were analyzed by direct sequencing. No pathologic mutations<br />
were identified in NPHS2 and WT1. However, two mutations, c.2172_<br />
2173delTG and c.2783C>A, were detected in the NPHS1 gene. The 2nucleotide<br />
deletion is predicted to create premature stop codon resulting<br />
in a truncated protein <strong>of</strong> 737 amino acids (E725GfsX13). The latter<br />
mutation changes codon 928 from serine (TCG) to a stop codon (TAG)<br />
(p.S928X). Both were novel mutations not described before. This is<br />
the first case <strong>of</strong> genetically-confirmed congenital nephrotic syndrome<br />
<strong>of</strong> the Finnish type in Hong Kong Chinese.<br />
P12.045<br />
A novel mutation <strong>of</strong> the ELA2 gene in a patient with severe<br />
congenital neutropenia<br />
M. Maschan 1 , M. Kurnikova 2 , A. Maschan 1 , I. Shagina 2 , D. Shagin 2,3 ;<br />
1 Federal Research Clinical Center for pediatric hematology, oncology and immunology,<br />
Moscow, Russian Federation, 2 Evrogen Joint Stock Company, Moscow,<br />
Russian Federation, 3 Shemyakin and Ovchinnikov Institute <strong>of</strong> Bioorganic<br />
Chemistry, RAS, Moscow, Russian Federation.<br />
Severe congenital neutropenia (SCN) is an inborn disorder <strong>of</strong> granulopoiesis.<br />
Mutations <strong>of</strong> the ELA2 gene encoding neutrophil elastase