Surface Rendering of External Genitalia of a Fetus at the 32nd Week of Gestation Affected by Partial Androgen Insensitivity Syndrome

Objectives. To demonstrate the feasibility of the prenatal diagnosis of partial androgen insensitivity syndrome by 3D-4D ultrasound. Methods. To report prenatal diagnosis of partial androgen insensitivity syndrome at 32nd week of gestation by 3D-4D ultrasound in a fetus with a 46XY karyotype, testing negative to the mutation analysis of SRY gene and the 5α-reductase 2 gene (SRD5A2). Results. 3D-4D surface rendering allows the detection of external and internal genital malformations and can address the prenatal diagnosis of PAIS and can exclude associated complications. Conclusions. Prenatal diagnosis of PAIS allows an adequate parental counseling and an early optimal management of the condition, not only for the psychological and social reflections but also for the avoidance of complications and postnatal morbidity due to misdiagnosis or delays in the treatment of the genital ambiguity

Convergent pathological and ultrasound features in hereditary syndromic and non\u2010syndromic minifascicular neuropathy related to DHH

Background: Minifascicular neuropathy (MN) is a rare, autosomal recessive disease with prominent structural changes of peripheral nerves. So far, it has been observed in females with a 46,XY karyotype and mutations of the Desert Hedgehog (DHH) gene, thus linking MN to gonadal dysgenesis (GD) and disorders of sex development (DSD). Methods and results: A 46,XX proband with normal female sex and gender development underwent clinical evaluations, nerve conduction studies and genetic screening for a severe motor-sensory neuropathy. Sural nerve biopsy revealed a profound disturbance of perineurium development with a thin and loose structure that hinted at MN. High-resolution ultrasound (HRUS) also disclosed diffuse changes of nerve echotexture that visibly correlated with the pathological features. After extensive genetic testing, a novel homozygous DHH null mutation (p.Ser185*) was identified in the proband and in her sister, who was affected by a similar motor-sensory neuropathy, but was eventually found to be a 46,XY patient according to a late diagnosis of DSD with complete GD. Interpretation: DHH should be considered as a possible cause of rare non-syndromic hereditary motor-sensory neuropathies, regardless of DSD. HRUS could effectively smooth the complex diagnostic workup as it demonstrated a high predictive power to detect MN, providing the same detailed correlations to the pathologic features of the nerve biopsy and Dhh-/- mice in both sisters. Hence, HRUS may assume a pivotal role in guiding molecular analysis in individuals with or without DSD

Hypercalcemia due to CYP24A1 mutations: a systematic descriptive review

Background and objectives: CYP24A1 encodes a 24-hydroxylase involved in vitamin D catabolism, whose loss-of-function results in vitamin D-dependent hypercalcemia. Since the identification of CYP24A1 variants as a cause of idiopathic infantile hypercalcemia, a large body of literature has emerged indicating heterogeneity in penetrance, symptoms, biochemistry, and treatments. The objectives of the present research work were to investigate the clinical heterogeneity of the disease, the possibility of a relevant phenotype for monoallelic carriers, and to compare the hypocalcemic effect of the available therapies. Methods: Two reviewers searched different databases for studies published between the identification of CYP24A1 variants and December 31, 2020. Eligible studies included clinical trials and reports describing carriers of CYP24A1 variants. Results: Fifty eligible studies were identified, accounting for 221 patients. Genetic data were retrieved and allele frequencies were calculated. Acute hypercalcemia was the typical presentation during the first year of life (76%, P = 0.0005), and nephrocalcinosis was more frequent in infancy (P < 0.0001). Pregnancy was associated with symptomatic hypercalcemia in 81.8% and high rates of obstetric complications. Monoallelic carriers displayed significant rates of nephrolithiasis (19.4%), nephrocalcinosis (4.9%), and symptomatic hypercalcemia (5.6%). Conclusions: CYP24A1 loss-of-function results in an age-dependent phenotype, which can be exacerbated by triggering factors, such as pregnancy. Although biallelic carriers present more significant clinical and biochemical features, monoallelic carriers have an increased risk of calcium-related conditions. The highly variable tested therapeutic approaches did not allow to draw conclusions on preferable therapeutic regime

Do the heterozygous carriers of a CYP24A1 mutation display a different biochemical phenotype than wild types?

Context: Human cytochrome P450 24 subfamily A member 1 (CYP24A1) loss-of-function mutations result in impaired activity of the 24-hydroxylase involved in vitamin D catabolism, thus inducing a vitamin D-dependent hypercalcemia. Homozygotes often present an overt clinical phenotype named Idiopathic Infantile hypercalcemia (IIH), whereas it is debated whether heterozygotes display an abnormal phenotype. Objectives: To compare the clinical and biochemical features of heterozygous carriers of CYP24A1 variant and healthy wild-type controls, sharing the same genetic and environmental exposure. Methods: A large family harboring the nonsense c.667A>T, p.Arg223* pathogenic variant in the CYP24A1 gene was evaluated. All subjects underwent clinical and biochemical evaluation and complete analysis of vitamin D metabolites using mass-spectroscopy including 1,24,25(OH)3D3. Subjects were divided according to their genotype in two groups: heterozygotes and wild-type for the CYP24A1 variant. Results: The proband, a 40-year-old man, homozygous for p.Arg223* pathogenic variant, had a history of mild hypercalcemia with a seasonal trend, recurrent nephrolithiasis, and no episodes of acute hypercalcemia. He showed the highest serum levels of FGF23, the highest 25(OH)D3/24,25(OH)2D3 ratio and undetectable levels of 1,24,25(OH)3D3 which represent indicators of a loss-of function CYP24A1. Compared to the wild-types, heterozygotes had higher serum calcium and 25(OH)D3 concentrations (P=0.017 and P=0.025, respectively), without any difference in the other biochemical parameters and in the rate of nephrolithiasis. Conclusions: Heterozygotes exhibit a biochemical phenotype different from that of wild-type subjects. In clinical practice, these individuals might require surveillance because of the potential risk of developing hypercalcemia and related clinical manifestations if exposed to triggering factors

Adolescent Gynecomastia due to Minimal Androgen Resistance Syndrome: A Case Report and Literature Review

A 14-year-old boy with a 46,XY karyotype and persistent breast-3-stage gynecomastia is reported. The reproductive axis was investigated by standard laboratory methods and the androgen receptor (AR) gene was sequenced. Also, a literature review of phenotypes associated with the AR genetic variant p.Pro392Ser was performed. The boy presented with height in the upper normal range (+1.9 SDS) and normal body mass index (-0,3 SDS); pubertal development was PH5/G4 (mean testicular volume 15 mL; 0 SDS). Laboratory findings were normal for age and sex, except aromatization index (0.09; reference range 0.03-0.07). Analysis of the AR gene showed the single nucleotide variant c.1174C>T (p.Pro392Ser) in exon 1, leading to the diagnosis of minimal androgen insensitivity syndrome (AIS). This genetic variant is reported in other 8 patients with AIS and is associated with variable clinical phenotypes ranging from complete to partial and minimal AIS. To the best of our knowledge, this is the first adolescent in whom the p.Pro392Ser mutation is associated with isolated persistent gynecomastia. The underlying reason of phenotypic variability due to this AR mutation remains unknown. Persistent gynecomastia due to minimal AIS has been reported in few additional males with variable AR mutations. Since fertility troubles may occur in adult men with minimal AIS, early diagnosis can allow optimizing the clinical management

5α-Reductase-2 Deficiency: Clinical Findings, Endocrine Pitfalls, and Genetic Features in a Large Italian Cohort

Clinical records (n = 24) with an established diagnosis of 5α-reductase-2 deficiency were reviewed. A previous misdiagnosis was present in about 70% (period from first observation to definitive diagnosis: 9.1 ± 10.8 years), and in 8 children gonadal removal was performed before certain diagnosis. Initial sex assignment was female in 16/24 (67%) and male in 8/24 (33%) cases. After diagnosis, sex re-assignment was performed in 5 babies (4 girls to male sex; 1 boy to female sex). Baseline testosterone/DHT ratio was diagnostic in 6/12 subjects (first months of life n = 4; puberty n = 2), while post-hCG testosterone/DHT ratio was diagnostic in all tested individuals (choosing both the cut-off value 15 or 10). Eighteen different mutations in the steroid-5α-reductase-2 (SRD5A2) gene were identified, 5 of which have never been reported. In conclusion, a time lag exists before the diagnosis of 5α-reductase-2 deficiency is established; sex assignment and gonadal removal may be performed before certain diagnosis. Sex re-assignment is usually female to male, but the contrary may occur. A large variability in clinical phenotypes and genetic mutations was present in this cohort. Accurate endocrine evaluation is recommended in babies possibly affected by 5α-reductase-2 deficiency, since the use of appropriate cut-off values of testosterone/DHT ratio after hCG stimulation may permit to select individuals for SRD5A2 gene analysis. A genotype-phenotype correlation was not found in this study

Hereditary spastic paraparesis in adults. A clinical and genetic perspective from Tuscany

Objective Hereditary spastic paraparesis or paraplegias (HSPs) are a group of neurogenetic conditions with prominent involvement of the pyramidal tracts. Aim of this study is the clinical and molecular characterization of a cohort of patients with HSP. Moreover, we aim to study the minimum prevalence of HSP in our area and to propose a schematic diagnostic approach to HSP patients based on the available data from the literature. Methods Retrospective/perspective study on the subjects with clinical signs and symptoms indicative of pure or complicated HSP, in whom other possible diagnosis were excluded by appropriate neuroradiological, neurophysiologic and laboratory studies, who have been evaluated by the Neurogenetic Service of our clinic in last two years (2011-2012). Results 45 patients were identified. The minimum prevalence of HSP in our area was of about 2.17-3.43/100,000. The SF-36 (quality of life) and SPRS (disease progression) scores were inversely related; the time-saving, four-stage scale of motor disability could predict the SPRS scores with a high statistical significance, and we encourage its use in HSP. Our study confirms SPG4 as the major cause of HSP. All SPG4 patients had a pure HSP phenotype, and the dominant inheritance was evident in the great majority of these subjects. SPG7 was the second genetic cause. Other genotypes were rarer (SPG10, SPG11, SPG17). Conclusion Exact molecular diagnosis will allow a more accurate patient counseling and, hopefully, will lead to specific, targeted, therapeutic options for these chronic, still incurable diseases. © 2014 Elsevier B.V

Ambiguous external genitalia due to defect of 5-α-reductase in seven Iraqi patients: Prevalence of a novel mutation

We report on seven Iraqi patients with 46,XY karyotype and ambiguous genitalia characterized by perineo-scrotal hypospadias, bifid scrotum, clitoris like phallus, palpable testes in inguinal canal and pseudovagina. Patients were raised five as females and two as males. They are all unrelated with the exception of two couples of brothers. The diagnosis of 5-α-reductase-2 deficiency syndromewas first hypothesized on clinical grounds and then confirmed by molecular analysis. Direct sequencing analysis of the SRD5A2 gene revealed in five patients a novel homozygous frame-shiftmutation (c.453delC) and in two related patients a previous reportedmissensemutation. The presence of the same mutation in unrelated patients of the same population suggests a possible founder effect. This report brings the 5-α-reductase-2 deficiency syndrome to the attention of clinical geneticists and child surgeons and discusses the appropriate clinical and surgical strategies for treating these patients