A rare form of ankyloblepharon filiforme adnatum associated with the Hay-Wells syndrome and a c.1709T>C mutation on the TP63 gene.

INTRODUCTION: Ankyloblepharon filiforme adnatum associated with Hay-Wells syndrome is a rare congenital disease caused by mutations in TP63 gene on the 3q27 chromosome. Here, we report a case of a new-born suffering from this syndrome in whom we detected a mutation c.1709T>C not previously included in the Ensemble database. CASE DESCRIPTION: A girl delivered in the 34th week of gestation from a physiological pregnancy was born with extensive burn-like skin defects, ankyloblepharon filiforme adnatum, palate cleft, onychodystrophy of all limbs and syndactyly of toes. Hay-Wells syndrome was suspected and confirmed by genetic examination. A heterozygous missense change c.1709T>C was found in the TP63 gene. This variant leads to a 570th codon exchange of leucine for proline (p.Leu570Pro) on the protein level. The eyelid separation was performed surgically, burns were treated locally and cosmetic surgeries correcting other defects are planned for the near future. The girl is still monitored by a multidisciplinary team. CONCLUSIONS: The mutation was not previously described in the literature or databases and should be included into these as probably pathogenic. A multidisciplinary approach is necessary to care for a patient with Hay-Wells syndrome, such care however can provide good results.

Disease-Causing Variants in the ATL1 Gene Are a Rare Cause of Hereditary Spastic Paraplegia among Czech Patients.

Variants in the ATL1 gene have been repeatedly described as the second most frequent cause of hereditary spastic paraplegia (HSP), a motor neuron disease manifested by progressive lower limb spasticity and weakness. Variants in ATL1 have been described mainly in patients with early onset HSP. We performed Sanger sequencing of all coding exons and adjacent intron regions of the ALT1 gene in 111 Czech patients with pure form of HSP and additional Multiplex-Ligation Probe Analysis (MLPA) testing targeting the ATL1 gene in 56 of them. All patients except seven were previously tested by Sanger sequencing of the SPAST gene with negative results. ATL1 diagnostic testing revealed only five missense variants in the ATL1 gene. Four of them are novel, but we suppose only two of them to be pathogenic and causal. The remaining variants are assumed to be benign. MLPA testing in 56 of sequence variant negative patients revealed no gross deletion in the ATL1 gene. Variants in the ATL1 gene are more frequent in patients with early onset HSP, but in general the occurrence of pathogenic variants in the ATL1 gene is low in our cohort, less than 4.5% and less than 11.1% in patients with onset before the age of ten. Variants in the ATL1 gene are a less frequent cause of HSP among Czech patients than has been previously reported among other populations.

Massively Parallel Sequencing Detected a Mutation in the MFN2 Gene Missed by Sanger Sequencing Due to a Primer Mismatch on an SNP Site.

We describe a patient with early onset severe axonal Charcot-Marie-Tooth disease (CMT2) with dominant inheritance, in whom Sanger sequencing failed to detect a mutation in the mitofusin 2 (MFN2) gene because of a single nucleotide polymorphism (rs2236057) under the PCR primer sequence. The severe early onset phenotype and the family history with severely affected mother (died after delivery) was very suggestive of CMT2A and this suspicion was finally confirmed by a MFN2 mutation. The mutation p.His361Tyr was later detected in the patient by massively parallel sequencing with a gene panel for hereditary neuropathies. According to this information, new primers for amplification and sequencing were designed which bind away from the polymorphic sites of the patient's DNA. Sanger sequencing with these new primers then confirmed the heterozygous mutation in the MFN2 gene in this patient. This case report shows that massively parallel sequencing may in some rare cases be more sensitive than Sanger sequencing and highlights the importance of accurate primer design which requires special attention.