GNRH1 Variants in Congenital Hypogonadotropic Hypogonadism: Single-Center Experience and Systematic Literature Review.

OBJECTIVE: As GNRH1 genotype-phenotype correlation in CHH is not well studied, we aim to describe the GNRH1 variants in our CHH cohort and present a systematic review as well as genotype-phenotype analysis of all mutation-positive cases reported in the world literature. DESIGN: This is a retrospective study of GNRH1 mutation-positive patients from a western Indian center. PRISMA guidelines-based PubMed search of the published literature of all GNRH1 mutation-positive patients was conducted. SETTING: This study was conducted in an academic medical center. PATIENT(S): This study included 2 probands from our cohort and 19 probands from the world literature. MAIN OUTCOME MEASURE(S): Demographic details, clinical presentation, biochemistry, imaging, treatment details, and genotypic data were recorded. RESULT(S): Two probands in our cohort carried two novel pathogenic biallelic GNRH1 variants (p.Glu24Leu, c.238-2A>G). Both had a severe reproductive phenotype. We report successful gonadotropin therapy and fertility in 1 proband. We included 19 probands from 12 studies after the literature review. Ten CHH probands (inclusive 2 from this study) with biallelic GNRH1 variants had severe reproductive phenotype, low gonadotropin levels, low/normal prolactin, normal pituitary imaging, and no extra-reproductive phenotype. Of seven biallelic variants reported, three were frameshift, two were splice-site, and two were missense mutations. All of them were pathogenic/likely pathogenic without oligogenicity. Of seven monoallelic GNRH1 variants reported in 11 probands, 4 had nonreproductive phenotype, 3 were benign/likely benign, and 4 were oligogenic. CONCLUSION(S): GNRH1 biallelic variants lead to severe reproductive phenotype, with low gonadotropin levels without nonreproductive features or oligogenicity. However, the role of GNRH1 monoallelic variants in CHH pathophysiology for reported variants remains questionable.

Regional genotypic variations in normosmic congenital hypogonadotropic hypogonadism: our experience and systematic review.

PURPOSE: To describe phenotype-genotype data of Asian-Indian normosmic congenital hypogonadotropic hypogonadism (nCHH) from our centre and perform a systematic review of genetic studies using next-generation sequencing (NGS) in nCHH. METHODS: Sixty-eight nCHH probands from our center, and 370 nCHH probands from published studies were included. Per-patient genetic variants were analyzed as per ACMG guidelines. Molecular diagnosis was defined as presence of a pathogenic or likely pathogenic variant in a known CHH gene following zygosity status as per known mode of genetic inheritance. RESULT: At our centre molecular diagnosis was observed in 35.3% of probands {GNRHR:16.2%, FGFR1:7.3%, KISS1R:4.4%, GNRH1:2.9%, TACR3:2.9%, CHD7:1.4%}. Molecular diagnosis was observed more often (44.7% vs 14.3%, p = 0.026) with severe than partial reproductive-phenotype. The study adds 12 novel variants and suggests GNRHR p.Thr32Ala variant may have a founder effect. In per-patient systematic review (including our cohort), the molecular diagnosis was reached in 23.2%, ranging from 3.5 to 46.7% at different centers. The affected genes were FGFR1:6.4%, GNRHR:4.3%, PROKR2:3.6%, TACR3:1.8%, CHD7:1.6%, KISS1R:1.4%, GNRH1:1.4% and others (PROK2, SOX3, SOX10, SOX11, IL17RD, IGSF10, TAC3, ANOS1, oligogenic): < 1% each. FGFR1 was the most commonly affected gene in most cohorts except Asia, whereas PROKR2 (in China and Japan) and GNRHR (in India) were the commonest. CONCLUSION: (s): The global molecular diagnosis rate was 23.2% in nCHH cohorts whereas that in our cohort was 35% with a higher rate (44.7%) in those with severe reproductive-phenotype. The most commonly affected gene in nCHH patients was FGFR1 globally while it was PROKR2 in East Asia and GNRHR in India.

Expanding the phenome and variome of skeletal dysplasia.

PURPOSE: To describe our experience with a large cohort (411 patients from 288 families) of various forms of skeletal dysplasia who were molecularly characterized. METHODS: Detailed phenotyping and next-generation sequencing (panel and exome). RESULTS: Our analysis revealed 224 pathogenic/likely pathogenic variants (54 (24%) of which are novel) in 123 genes with established or tentative links to skeletal dysplasia. In addition, we propose 5 genes as candidate disease genes with suggestive biological links (WNT3A, SUCO, RIN1, DIP2C, and PAN2). Phenotypically, we note that our cohort spans 36 established phenotypic categories by the International Skeletal Dysplasia Nosology, as well as 18 novel skeletal dysplasia phenotypes that could not be classified under these categories, e.g., the novel C3orf17-related skeletal dysplasia. We also describe novel phenotypic aspects of well-known disease genes, e.g., PGAP3-related Toriello-Carey syndrome-like phenotype. We note a strong founder effect for many genes in our cohort, which allowed us to calculate a minimum disease burden for the autosomal recessive forms of skeletal dysplasia in our population (7.16E-04), which is much higher than the global average. CONCLUSION: By expanding the phenotypic, allelic, and locus heterogeneity of skeletal dysplasia in humans, we hope our study will improve the diagnostic rate of patients with these conditions.

The Cockayne Syndrome Natural History (CoSyNH) study: clinical findings in 102 individuals and recommendations for care.

PURPOSE: Cockayne syndrome (CS) is a rare, autosomal-recessive disorder characterized by microcephaly, impaired postnatal growth, and premature pathological aging. It has historically been considered a DNA repair disorder; fibroblasts from classic patients often exhibit impaired transcription-coupled nucleotide excision repair. Previous studies have largely been restricted to case reports and small series, and no guidelines for care have been established. METHODS: One hundred two study participants were identified through a network of collaborating clinicians and the Amy and Friends CS support groups. Families with a diagnosis of CS could also self-recruit. Comprehensive clinical information for analysis was obtained directly from families and their clinicians. RESULTS AND CONCLUSION: We present the most complete evaluation of Cockayne syndrome to date, including detailed information on the prevalence and onset of clinical features, achievement of neurodevelopmental milestones, and patient management. We confirm that the most valuable prognostic factor in CS is the presence of early cataracts. Using this evidence, we have created simple guidelines for the care of individuals with CS. We aim to assist clinicians in the recognition, diagnosis, and management of this condition and to enable families to understand what problems they may encounter as CS progresses.Genet Med 18 5, 483-493.

Clinical and mutation profile of multicentric osteolysis nodulosis and arthropathy.

​Multicentric osteolysis nodulosis and arthropathy (MONA) is an infrequently described autosomal recessive skeletal dysplasia characterized by progressive osteolysis and arthropathy. Inactivating mutations in MMP2, encoding matrix metalloproteinase-2, are known to cause this disorder. Fifteen families with mutations in MMP2 have been reported in literature. In this study we screened thirteen individuals from eleven families for MMP2 mutations and identified eight mutations (five novel and three known variants). We characterize the clinical, radiographic and molecular findings in all individuals with molecularly proven MONA from the present cohort and previous reports, and provide a comprehensive review of the MMP2 related disorders.

Isoleucine Deficiency in a Neonate Treated for Maple Syrup Urine Disease Masquerading as Acrodermatitis Enteropathica.

BACKGROUND: Special diet with restricted branched-chain-amino-acids used for treating maple syrup urine disease can lead to specific amino acid deficiencies. CASE CHARACTERISTICS: We report a neonate who developed skin lesions due to isoleucine deficiency while using specialised formula. INTERVENTION/OUTCOME: Feeds were supplemented with expressed breast milk. This caused biochemical and clinical improvement with resolution of skin lesions. MESSAGE: Breast milk is a valuable and necessary adjunct to specialized formula in maple syrup urine disease to prevent specific amino acid deficiency in the neonatal period.

Recurrent and novel GLB1 mutations in India.

GM1 gangliosidosis is a lysosomal storage disorder caused by mutations in the GLB1 gene, leading to the deficiency of the enzyme ß-d-galactosidase. In this study, we report molecular findings in 50 Asian Indian families with GM1 gangliosidosis. We sequenced all the exons and flanking intronic sequences of GLB1 gene. We identified 33 different mutations (20 novel and 13 previously reported). The novel mutations include 12 missense (p.M1?, p.E129Q, p.G134R, p.L236P, p.G262E, p.L297F, p.Y331C, p.G414V, p.K493N, p.L514P, p.P597L, p.T600I), four splicing (c.246-2A>G, c.397-2A>G, c.552+1G>T, c.956-2A>G), three indels (p.R22Qfs*8, p.L24Cfs*47, p.I489Qfs*4) and one nonsense mutation (p.Q452*). Most common mutations identified in this study were c.75+2InsT (14%) and p.L337P (10%). Known mutations accounted for 67% of allele frequency in our cohort of patients, suggesting that these mutations in GLB1 are recurrent across different populations. Twenty three mutations were localized in the TIM barrel domain, ß-domain 1 and ß-domain 2. In silico sequence and structure analysis of GLB1 reveal that all the novel mutations affect the function and structure of the protein. We hereby report on the largest series of patients with GM1 gangliosidosis and the first from India.

MURCS association with situs inversus totalis: Expanding the spectrum or a novel disorder.

We are reporting a female patient with a MURCS association (Müllerian duct aplasia, unilateral renal agenesis, cervico-thoracic somite fusion defects), situs inversus totalis, short stature with normal development and intelligence. We are presenting the comparison with two other patients published with similar finding. Our patient is distinct in having all the characteristic features and represents the severe spectrum of this disorder. We present our argument favoring this to be a monogenic syndrome distinct from the other two entities and probably a ciliopathy.

Patient with mutation in the matrix metalloproteinase 2 (MMP2) gene - a case report and review of the literature.

Torg and Winchester syndromes and patients reported by Al-AqeelSawairi as well as nodulosis-arthropathy-osteolysis (NAO) patients, patients with multicentric NAO share autosomal recessive inheritance. The common presenting symptomatology includes progressive osteolysis chiefly affecting the carpal, tarsal and interphalangeal joints. Here, we report a patient with Torg syndrome. Torg syndrome is caused by homozygous or compound heterozygous mutations in the matrix metalloproteinase 2 (MMP2) gene. MMP2 codes for a gelatinase that cleaves type IV collagen, a major component of basement membrane. The clinical presentation of our patient included moderate osteolysis of the small joints of the hands and knees, hirsutism, nodulosis sparing the palms and soles, corneal opacities and mild facial dysmorphism without gum hypertrophy. Genetic analysis showed that the patient was homozygous for a novel base variant c538 G>A (p.D180N) in the MMP2 gene. Both parents were carriers of the same mutated variant. Our patient had some previously unreported endocrine manifestations such as premature thelarche and elevated follicle-stimulating hormone levels.

A descriptive analysis of 14 cases of progressive-psuedorheumatoid-arthropathy of childhood from south India: review of literature in comparison with juvenile idiopathic arthritis.

BACKGROUND: Progressive-psuedorheumatoid-arthropathy of childhood (PPAC) is an autosomal recessive single gene skeletal dysplasia involving joints. The gene attributed to its cause is WNT1-inducible-signaling pathway protein3 (WISP3). OBJECTIVE: To study the clinical and radiographic presentation of PPAC in Indian patients and to compare with described features of PPAC and Juvenile Idiopathic Arthritis (JIA) from published literature. METHODS: All cases (n = 14) of PPAC seen in the Rheumatology and Clinical Genetics outpatient clinic between 2008 and 2011 with classical, clinical, and radiological features were studied. The demographic and clinical data were obtained from medical records of the outpatient visits. RESULTS: Slight female preponderance (57%) and history of consanguinity in parents (43%) was observed in this group. The median age at onset was 4.5 years (range from birth to 9 years of age). Early presentation below the age of 3 years was seen in 3/14 patients (21%) in this group. The growth of all the patients fell below the 3rd percentile for the age. Historically, hip joint involvement was the most common presenting feature; however, elbow, wrist, knees, feet, spine, shoulder joints and small joints, namely proximal interphalangeal (PIP), distal interphalangeal (DIP), metacarpophalangeal (MCP), metatarsophalangeal joints (MTP), and interphalangeal joints (IP) of the feet, were also involved, either clinically or radiologically in varying proportions. Platyspondyly was noted in all. Molecular analysis of the WISP3 gene identified mutations in all the 5 individuals in whom it was done. CONCLUSION: This descriptive case series of PPAC from India reports distinctly differentiating clinical, radiological, and molecular markers in contrast with classically described features of JIA, its mimic. Early presentation (age of onset below 3 years) with involvement of interphalangeal joints seen in three patients (21%) was a unique finding, with missense WISP3 gene mutations in all of them. Timely diagnosis of this entity can spare the patient from unnecessary investigations and toxic medications.

A case report of fibular aplasia, tibial campomelia, and oligosyndactyly (FATCO) syndrome associated with Klinefelter syndrome and review of the literature.

UNLABELLED: Limb development is a complex regulated development phenomenon involving multiple genes. Fibular Aplasia, Tibial Campomelia and Oligosyndactyly (FATCO) syndrome (MIM#246570) is a syndrome of unknown genetic basis and inheritance with variable expressivity and penetrance. Its counterpart, Fuhrmann syndrome or Femoral-Fibularaplasia-Campomelia and Oligosyndactyly are a result of defect in the WNT7a gene located on the 3p25. Former is proposed to be a development dysplasia of defective dorso-ventral polarity assignment and distal limb development. Ectrodactyly and fibular a/hypoplasia (EFA, MIM# 113310) share the full phenotypic spectrum of FATCO syndrome, whether they are allelic disorders or represent two variable presentations in the spectrum of the same disorder is not an established fact. We report here one Indian patient with findings of FATCO syndrome with associated Klinefelter syndrome. This is the first such report which is likely to be a co-incidental finding and has implications for genetic counseling. LEVELS OF EVIDENCE: Therapeutic, Level IV.