Whole-exome sequencing identifies a GREB1L variant in a three-generation family with Müllerian and renal agenesis: a novel candidate gene in Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome. A case report.

The aetiology of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome, characterized by uterovaginal agenesis in 46,XX women, remains poorly understood. Since familial occurrences are rare, genetic findings reported so far only apply to a minority of mainly sporadic cases and most studies have not included other family members enabling segregation analysis. Herein, we report on the investigation of a unique three-generation family of two female cousins with MRKH syndrome and unilateral renal agenesis (RA) and two deceased male relatives with RA. We performed whole-exome sequencing (WES) in eight family members leading to the identification of a novel pathogenic (CADD = 33) c.705G>T missense variant in GREB1L, a gene recently identified as a novel cause of RA. Previous reports include several cases of female fetuses with bilateral RA and uterus agenesis, which support GREB1L as an important gene in both kidney and female genital tract development. The pedigree is compatible with autosomal dominant inheritance with incomplete penetrance following a parent-origin-specific manner, which could be due to imprinting. To our knowledge, this is the first investigation of a larger MRKH syndrome pedigree using WES, and we suggest GREB1L as a novel and promising candidate gene in the aetiology of MRKH syndrome.

First reported adult patient with TARP syndrome: A case report.

TARP syndrome (talipes equinovarus, atrial septal defect, Robin sequence, and persistence of the left superior vena cava) is a rare X-linked syndrome often resulting in pre- or post-natal lethality in affected males. In 2010, RBM10 was identified as the disease-causing gene, and we describe the first adult patient with TARP syndrome at age 28 years, hereby expanding the phenotypic spectrum. Our patient had Robin sequence, atrial septal defect, intellectual disability, scoliosis, and other findings previously associated with TARP syndrome. In addition, he had a prominent nose and nasal bridge, esotropia, displacement of lacrimal points in the cranial direction, small teeth, and chin dimple, which are the findings that have not previously been associated with TARP syndrome. Our patient was found to carry a hemizygous c.273_283delinsA RBM10 mutation in exon 4, an exon skipped in three of five protein-coding transcripts, suggesting a possible explanation for our patient surviving to adulthood. Direct sequencing of maternal DNA indicated possible mosaicism, which was confirmed by massive parallel sequencing. One of two sisters were heterozygous for the mutation. Therefore, we recommend sisters of patients with TARP syndrome be carrier tested before family planning regardless of carrier testing results of the mother. Based on our patient and previously reported patients, we suggest TARP syndrome be considered as a possible diagnosis in males with severe or profound intellectual disability combined with septal heart defect, and Robin sequence, micrognathia, or cleft palate.

Surfactant protein D is a candidate biomarker for subclinical tobacco smoke-induced lung damage.

Variation in surfactant protein D (SP-D) is associated with lung function in tobacco smoke-induced chronic respiratory disease. We hypothesized that the same association exists in the general population and could be used to identify individuals sensitive to smoke-induced lung damage. The association between serum SP-D (sSP-D) and expiratory lung function was assessed in a cross-sectional design in a Danish twin population (n = 1,512, 18-72 yr old). The adjusted heritability estimates for expiratory lung function, associations between SP-D gene (SFTPD) single-nucleotide polymorphisms or haplotypes, and expiratory lung function were assessed using twin study methodology and mixed-effects models. Significant inverse associations were evident between sSP-D and the forced expiratory volume in 1 s and forced vital capacity in the presence of current tobacco smoking but not in nonsmokers. The two SFTPD single-nucleotide polymorphisms, rs1923536 and rs721917, and haplotypes, including these single-nucleotide polymorphisms or rs2243539, were inversely associated with expiratory lung function in interaction with smoking. In conclusion, SP-D is phenotypically and genetically associated with lung function measures in interaction with tobacco smoking. The obtained data suggest sSP-D as a candidate biomarker in risk assessments for subclinical tobacco smoke-induced lung damage. The data and derived conclusion warrant confirmation in a longitudinal population following chronic obstructive pulmonary disease initiation and development.

Familial occurrence of Mayer-Rokitansky-Küster-Hauser syndrome: a case report and review of the literature.

Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome is a congenital disorder of still unknown etiology, characterized by uterovaginal agenesis and can be associated with renal, skeletal and cardiac malformations. Most cases are sporadic. We report on a familial case of two female cousins with MRKH syndrome and unilateral renal agenesis. Family history revealed two cases of renal agenesis in male relatives and ultrasonographic (US) examination of healthy relatives diagnosed an uncle with multiple renal cysts. We have reviewed the literature on familial occurrence of MRKH syndrome and its associated anomalies and collected a total of 67 familial cases. We found familial cases to share the same associated anomalies as sporadic cases and we discuss the necessity of US examination of healthy relatives.

The PHF6 Mutation c.1A>G; pM1V Causes Börjeson-Forsman-Lehmann Syndrome in a Family with Four Affected Young Boys.

The family presented with 4 boys, 2 sets of brothers, with unexplained intellectual disability. Numerous analyses had been conducted over more than a decade, without reaching a final clinical or molecular diagnosis. According to the pedigree, an X-linked inheritance pattern was strongly suspected. Whole-exome sequencing (WES) with targeted analysis of the coding regions of the X chromosome was carried out in the 4 boys, their mothers, and their shared grandmother. A filtering process searching for nonsynonymous variants and variants in the exon-intron boundaries revealed one variant, c.1A>G; pM1V, in the first codon of the PHF6 gene. The variant was hemizygous in the 4 boys and heterozygous in the 2 mothers and the grandmother. Mutations in the PHF6 gene are known to cause Börjeson-Forsman-Lehmann syndrome (BFLS). The boys were reexamined after the finding of the mutation, and the phenotype fitted perfectly with BFLS. The mutation found in the PHF6 gene is causative for the intellectual disability in this family. We also conclude that WES of the X chromosome is a powerful tool in families where an X-linked inheritance pattern is suspected.