Long-term follow-up and novel variant in Suleiman-El-Hattab syndrome: Expanding the genotypic and clinical spectrum of a rare neurodevelopmental disorder.

Suleiman-El-Hattab syndrome (SULEHS, OMIM #618950) is an autosomal recessive multisystem developmental disorder characterized by distinctive facial appearance, global developmental delay/intellectual disability, poor expressive speech and happy demeanor. SULEHS is an ultra-rare disorder associated with biallelic loss-of-function variants of the TASP1 gene, and up-to-date, seven patients from five families have been reported in the literature. Loss of TASP1 function has been reported to alter H3K4 histone modifications and expression of TFIIA and HOX transcription factors in the SULEHS phenotype. In this report, a new patient molecularly diagnosed with SULEHS by a novel homozygous c.404-2A > G variant in the TASP1 gene is presented with the long-term follow-up. Although the majority of the patient's clinical characteristics were similar to those of previously reported SULEHS patients, this study was the first to describe some additional anomalies, such as cystic hygroma, increased nuchal thickness, coarctation of the aorta, pulmonary stenosis, pulmonary sequestration anomaly, chronic constipation, encephalomalacia, and aggressive behavior. Because of the remarkable similarities between the clinical features of Baraitser-Winter syndrome (BRWS) and the patient, BRWS was considered the most likely diagnosis before the molecular diagnosis. Network analysis also supported that the interaction of the SULEHS-associated TASP1 gene with the BRWS-associated ACTB and ACTG1 genes through common intermediate molecules. Overall, despite the existence of differences in clinical features, inheritance patterns, and underlying pathophysiology between BRWS and SULEHS, both diseases could be considered in the differential diagnosis due to the high clinical similarities, including the dysmorphic features, growth parameters, neurodevelopmental phenotype, neurological problems, and multisystem involvement. Additionally, this report could contribute to a better understanding of the genotypic and clinical features of SULEHS by describing a novel pathogenic variant and new clinical features, such as prenatal manifestations.

A de novo heterozygous HOXA11 variant in a patient with mesomelic dysplasia with urogenital abnormalities.

Mesomelic dysplasias are a genetically and clinically heterogeneous group of diseases with more than 10 types defined. This article presents an 18-year-old female patient with normal intelligence and a multisystem phenotype including disproportionate short stature, scoliosis, mesomelic limb shortening, radial bowing, short fourth to fifth metacarpals and metatarsals, fusions in the carpal/tarsal bones, operated pes equinovarus, primary amenorrhea, uterine hypoplasia, vesicoureteral reflux, and chronic kidney disease. Whole-exome sequencing revealed a de novo heterozygous c.881T>G (p.Met294Arg) variant in HOXA11 (NM_005523.6) gene. The variant was located in the homeodomain of HOXA11 and predicted to alter DNA-binding ability of the protein. In silico analyses indicated that the variant could promote the alterations in the protein-protein interaction. The possible functional effect of the variant was supposed as dominant-negative. Hoxa11-mutant mice have been reported to exhibit homeotic transformations in the thoracic and sacral vertebrae, zeugopodal phenotype in forelimb and hindlimb, and urogenital abnormalities. Although mice models were reported as mesomelic dysplasia and urogenital abnormalities (MDUGA), this phenotype has not yet been reported in humans. This was the first case with MDUGA putatively related to a de novo variant in HOXA11.

Warburg Micro Syndrome 1 due to Segmental Paternal Uniparental Isodisomy of Chromosome 2 Detected by Whole-Exome Sequencing and Homozygosity Mapping.

Warburg micro syndrome (WARBM) is a rare autosomal recessive disorder characterized by microcephaly, cortical dysplasia, intellectual disability, ocular abnormalities, spastic diplegia, and microgenitalia. WARBM has 4 subtypes arising from pathogenic variants in 4 genes (RAB18, RAB3GAP1, RAB3GAP2, and TBC1D20). Here, we report on a patient with a homozygous pathogenic c.665delC (p.Pro222HisfsTer30) variant in the RAB3GAP1 gene identified by whole-exome sequencing (WES) analyses. Only his father was a heterozygous carrier, and homozygosity mapping analysis of the WES data revealed large loss-of-heterozygosity regions in both arms of chromosome 2, interpreted as uniparental isodisomy. This uniparental disomy pattern could be due to paternal meiosis I nondisjunction because of the preserved heterozygosity in the pericentromeric region. This report provides novel insights, including a rare form of UPD, usage of homozygosity mapping analysis for the evaluation of isodisomy, and the first reported case of WARBM1 as a result of uniparental isodisomy.

46 XX male syndrome with hypogonadotropic hypogonadism: A case report.

We report a 46 XX male syndrome diagnosed after failure of gonadotropin therapy taken for hypogonadotropic hypogonadism due to a pituitary macroadenoma. A 39-year-old man with a non-functioning pituitary macroadenoma was admitted to our clinic due to vision loss and infertility. After pituitary surgery, vision loss improved while infertility still existed. Low testosterone levels without elevated gonadotropins were established suggesting hypogonadotropic hypogonadism due to pituitary adenoma. Gonadotropin treatment was initiated. There was no response to treatment after 12 months. A karyotype analysis was ordered to investigate other causes of infertility. Karyotype analysis showed a 46 XX male syndrome that can explain the failure of gonadotropin therapy. Testosterone therapy was started instead of gonadotropin therapy. 46 XX male syndrome usually presents with hypergonadotropic hypogonadism. However, in our case, it presented with hypogonadotropic hypogonadism due to pituitary mass not responding to gonadotropin therapy. It is important to keep in mind to obtain a genetic analysis of patients whose gonadotropin therapy failed, even if their gonadotropin levels are not elevated.

Identification of Three Novel FBN1 Mutations and Their Phenotypic Relationship of Marfan Syndrome.

BACKGROUND: Marfan syndrome (MS), a connective tissue disorder that affects ocular, skeletal, and cardiovascular systems, is caused by heterozygous pathogenic variants in FBN1. To date, over 1800 different pathogenic variants have been reported. METHODS: In the present study, FBN1 sequence analysis was performed in a family and two unrelated patients with MS. RESULTS: Three novel pathogenic variants were detected. Two of these variants [c.6610T>C; p.(Cys2204Arg) and c.1956T>G; p.(Cys652Trp)], which affect a cysteine residue, were associated with MS with ectopia lentis, whereas the mutation causing a premature stop codon [c.2506delA; p.(Ser836ValfsX10)] leads to a classical MS of a milder phenotype. CONCLUSION: We anticipate that the three novel pathogenic variants identified in this study will provide further support for the clinical relevance of variants in the large FBN1 gene.

Influence of Folate-Related Gene Polymorphisms on High-Dose Methotrexate-Related Toxicity and Prognosis in Turkish Children with Acute Lymphoblastic Leukemia.

OBJECTIVE: High-dose methotrexate (HD-MTX) is widely used in the consolidation phase of childhood acute lymphoblastic leukemia (ALL), but the roles that polymorphisms in folate-related genes (FRGs) play in HD-MTX toxicity and prognosis in children with ALL are not understood. The aims of this study were to investigate the frequencies of polymorphisms in the genes for thymidylate synthase (TS), methionine synthase reductase (MTRR), and methylene tetrahydrofolate reductase (MTHFR) in Turkish children with ALL and to assess associations between these polymorphisms and HD-MTX-related toxicity and leukemia prognosis in this patient group. MATERIALS AND METHODS: FRG polymorphisms were assessed by real-time polymerase chain reaction. Survival status, MTX levels, and toxicity data were retrieved from 106 patients' charts. RESULTS: The allele frequencies for the FRG polymorphisms were as follows: TS 2R 41.0%, 3R 57.0%, and 4R 2.0%; MTRR 66A 42.4% and 66G 57.6%; MTHFR 677C 59.3% and 677T 40.7%; and MTHFR 1298A 58.1% and 1298C 41.9%. At the 48th hour of HD-MTX infusion, serum MTX was significantly higher in patients who had TS 2R/3R/4R variants as compared to those with wild-type TS (p<0.05). No significant differences were detected with respect to event-free survival or toxicity between wild-type and other FRG variants. CONCLUSION: The frequencies of FRG polymorphisms in Turkish children with ALL are similar to those reported in other Caucasian populations. This is the first published finding of the TS 3R/4R variant in the Turkish population. The results indicate that HD-MTX can be tolerated by leukemic children with some polymorphic variants of FRG; thus, it may prevent future risk of leukemic relapse.

TMCO1 deficiency causes autosomal recessive cerebrofaciothoracic dysplasia.

Cerebrofaciothoracic dysplasia (CFT) (OMIM #213980) is a multiple congenital anomaly and intellectual disability syndrome involving the cranium, face, and thorax. The characteristic features are cranial involvement with macrocrania at birth, brachycephaly, various CT/MRI findings including hypoplasia of corpus callosum, enlargement of septum pellicidum, and diffuse hypodensity of the grey matter, flat face, hypertelorism, cleft lip and cleft palate, low-set, posteriorly rotated ears, short neck, and multiple costal and vertebral anomalies. The underlying genetic defect remains unknown. Using combination of homozygosity mapping and whole-exome sequencing, we identified a homozygous nonsense founder mutation, p.Arg87Ter (c.259 C>T), in the human transmembrane and coiled-coil domains protein 1 (TMCO1) in four out of five families of Turkish origin. The entire critical region on chromosome 1q24 containing TMCO1 was excluded in the fifth family with characteristic findings of CFT providing evidence for genetic heterogeneity of CFT spectrum. Another founder TMCO1 mutation has recently been reported to cause a unique genetic condition, TMCO1-defect syndrome (OMIM #614132). TMCO1-defect syndrome shares many features with CFT. This study supports the fact that "TMCO1-defect syndrome," initially thought to represent a distinct disorder, indeed belongs to the genetically heterogeneous CFT dysplasia spectrum.

Rectal duplications accompanying rectovestibular fistula: report of two cases.

Rectal duplication (RD) cysts are rare congenital anomalies that can be diagnosed with the presence of another opening in the perineum. They seldom accompany anorectal malformations (ARM). Two cases of RD accompanying ARM at opposite ends of the phenotypic spectrum, are described. A 3-month-old baby and a 2-year-old girl with ARM were scheduled for posterior sagittal anorectoplasty. The infant had an orifice at the anal dimple and the other had an orifice at the vestibulum posterior to the rectovestibular fistula. The infant presented with no other anomalies whereas the older one presented with an unusual coexistence of caudal duplication and caudal regression syndromes. Perioperatively both orifices were found to be related to retrorectal cysts, and were excised. Clinicians should always be alert when dealing with complex malformations. Because these malformations have variable anatomical and clinical presentations, they can represent a diagnostic and therapeutic challenge.

A Turkish family with Nance-Horan Syndrome due to a novel mutation.

Nance-Horan Syndrome (NHS) is a rare X-linked syndrome characterized by congenital cataract which leads to profound vision loss, characteristic dysmorphic features and specific dental anomalies. Microcornea, microphthalmia and mild or moderate mental retardation may accompany these features. Heterozygous females often manifest similarly but with less severe features than affected males. We describe two brothers who have the NHS phenotype and their carrier mother who had microcornea but not cataract. We identified a previously unreported frameshift mutation (c.558insA) in exon 1 of the NHS gene in these patients and their mother which is predicted to result in the incorporation of 11 aberrant amino acids prior to a stop codon (p.E186Efs11X). We also discussed genotype-phenotype correlation according to relevant literature.

Duplication 4q associated with chronic cholestatic changes in liver biopsy.

We report a 15-day-old girl with partial trisomy 4q syndrome who presented with neonatal cholestasis. She had dysmorphic facial features and preaxial polysyndactyly of the right hand. The other findings were generalized hypertrichosis, pes equinovarus, oedema on feet and mild hepatomegaly. No specific reason for the cholestasis with elevated liver enzymes and direct bilirubinemia were characterized. Cytogenetic analyses revealed a karyotype 46,XX,der(13)t(4;13)(q25;p13). This is the first patient with partial trisomy 4q syndrome presented with neonatal cholestasis.

LRP4 mutations alter Wnt/beta-catenin signaling and cause limb and kidney malformations in Cenani-Lenz syndrome.

Cenani-Lenz syndrome (CLS) is an autosomal-recessive congenital disorder affecting distal limb development. It is characterized mainly by syndactyly and/or oligodactyly and is now shown to be commonly associated with kidney anomalies. We used a homozygosity-mapping approach to map the CLS1 locus to chromosome 11p11.2-q13.1. By sequencing candidate genes, we identified recessive LRP4 mutations in 12 families with CLS. LRP4 belongs to the low-density lipoprotein (LDL) receptor-related proteins (LRPs), which are essential for various developmental processes. LRP4 is known to antagonize LRP6-mediated activation of canonical Wnt signaling, a function that is lost by the identified mutations. Our findings increase the spectrum of congenital anomalies associated with abnormal lipoprotein receptor-dependent signaling.

A case with a ring chromosome 22.

Ring chromosome 22, a rare cytogenetic finding, was first described in 1968, and since then about 60 patients have been reported. We describe a new patient with ring chromosome 22 syndrome and discuss the common features of the previously reported cases. Our patient had the major features of this syndrome including mental retardation, hypotonia, motor delay, microcephaly, dysplastic large ears, lack of speech, and hyperactivity disorder. Magnetic resonance imaging findings also revealed an arachnoid cyst, found in the posterior cerebellum. In patients with ring chromosome 22, variable clinical manifestations may be seen due to the size of lost sequences near the telomere. By fluorescent in situ hybridization (FISH) technique, LSI DiGeorge/VCFS/ ARSA locus-specific probes are used to detect deleted sequences. We found that 22q11.2 regions were intact on both chromosomes 22, but 22q13.3 (Arylsulfatase A; ARSA region) was absent in the ring chromosome. As far as we know this is the first reported Turkish patient in the literature.

Spondyloepiphyseal dysplasia tarda with progressive arthropathy.

Spondyloepiphyseal dysplasia tarda with progressive arthropathy (SEDT-PA) is a rare autosomal recessive skeletal dysplasia affecting primarily the articular cartilage. Here we present a nine-year-old girl from Middle Anatolia (Sivas) with SEDT-PA. Her complaints were pain and progressive deformity of the joints. She had a short stature with increased thoracic kyphosis and lumbar lordosis. The range of motion was limited in the spine and the peripheral joints and she had deformities. Radiologic examination revealed generalized platyspondyly and irregularity of the vertebral endplates. There was minimal joint space narrowing at proximal interphalangeal joints, but there were no bone erosions. Metaphyses were widened and epiphyses were squared in other joints with generalized osteopenia and severe osteoarthritic changes prominent in hips. Laboratory examination revealed a mild increase in acute phase reactants. Genetic disorders like SEDT-PA may also have rheumatological involvement, so they should be kept in mind in differential diagnosis of inflammatory joint diseases.