IMAGe syndrome, a rare disorder caused by maternally inherited CDKN1C pathogenic variants, is characterized by intrauterine growth retardation (IUGR), metaphyseal dysplasia, adrenal hypoplasia congenita, and genitourinary abnormalities. We report a novel intronic CDKN1C variant in a 5-year-old Iranian girl with IMAGe syndrome. Clinical evaluations showed severe IUGR (birth weight 1850 g), disproportionate short stature (height 88 cm, -4.4 Z score), metaphyseal dysplasia, adrenal insufficiency (ACTH 1110 pg/mL, low cortisol), and dysmorphic features (frontal bossing, low-set ears). Whole-exome sequencing (WES) was performed to identify causative genetic variants. WES revealed a heterozygous CDKN1C intronic variant, c.787+4A>T, absent from gnomAD, ExAC, and ClinVar. SpliceAI (score: 0.82) predicted disrupted splicing, potentially leading to a gain-of-function effect. The variant was consistently classified as a Variant of Uncertain Significance (VUS) according to ACMG/AMP 2015 guidelines with 2020 updates. No other pathogenic variants were identified in genes related to skeletal dysplasia, adrenal insufficiency, or growth retardation. Sanger sequencing confirmed maternal inheritance in the proband, her healthy mother, and grandfather, consistent with CDKN1C paternal imprinting. This case broadens the genetic spectrum of IMAGe syndrome by identifying the first reported intronic CDKN1C variant associated with this condition. WES is crucial for diagnosis, and RNA analysis is needed to confirm the variant's functional impact. Rapid diagnosis is essential for managing life-threatening adrenal insufficiency.

The authors present a case of a 22-year-old female with a history of intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenita, and genital anomalies syndrome (IMAGe) secondary to pathogenic variants in the polymerase epsilon (POLE) gene who was newly diagnosed with type 2 diabetes. The patient was noted on routine lab work to have elevated blood glucose, and subsequent laboratory analysis revealed a hemoglobin A1c of 8.9% with normal serum insulin concentrations and negative autoimmune evaluation. She did not have physical exam findings or stigmata of insulin resistance. A continuous glucose monitor revealed significant postprandial hyperglycemia. She was initially treated with prandial insulin and was later transitioned to oral sitagliptin due to adherence and administration difficulties. To the best of our knowledge, this is one of the first patients with POLE-mediated IMAGe syndrome to be diagnosed with type 2 diabetes. Given the presence of adrenal insufficiency in this population and the lifelong need for glucocorticoid therapy, special care should be taken when dosing glucocorticoids to reduce the risk of the patient developing insulin resistance. Further research is needed to determine if type 2 diabetes is part of the phenotype for these genetic variants and to elucidate the associated underlying pathophysiology.

Mirror syndrome is a rare disease characterized by "triple edema", while Hemolytic Uremic Syndrome (PHUS) is a serious disease that occurs within a short period of time after the end of pregnancy, with a low prevalence and poor prognosis, and it is even rarer for both to occur in the same patient. We report a case of mirror syndrome combined with PHUS and analyze the clinical data to improve the understanding of the disease. The patient presented clinically with "triple edema" and was diagnosed with mirror image syndrome. After cesarean section, the patient developed cardiac insufficiency, renal insufficiency, hemolysis, and other symptoms and was diagnosed as PHUS. After active treatment, the maternal prognosis was good. Mirror syndrome and PHUS are both clinically rare diseases with poor long-term prognosis if not diagnosed and treated in a timely manner; therefore, awareness of the diseases, early and accurate diagnosis and timely and correct treatment should be improved.

Cyclin-dependent kinase inhibitor 1C (CDKN1C) is a cell proliferation inhibitor that regulates the cell cycle and cell growth through G1 cell cycle arrest. CDKN1C mutations can lead to IMAGe syndrome (CDKN1C allele gain-of-function mutations lead to intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenital, and genitourinary malformations). We present a Silver-Russell syndrome (SRS) pedigree that was due to a missense mutation affecting the same amino acid position, 279, in the CDKN1C gene, resulting in the amino acid substitution p.Arg279His (c.836G>A). The affected family members had an SRS phenotype but did not have limb asymmetry or adrenal insufficiency. The amino acid changes in this specific region were located in a narrow functional region that contained mutations previously associated with IMAGe syndrome. In familial SRS patients, the PCNA region of CDKN1C should be analysed. Adrenal insufficiency should be excluded in all patients with functional CDKN1C variants. We describe the case of an 8-year-old girl who initially presented with short stature. Her height was 91.6 cm, and her weight was 10.2 kg. Physical examination revealed that she had a relatively large head, an inverted triangular face, a protruding forehead, a low ear position, sunken eye sockets, and irregular cracked teeth but no limb asymmetry. Family history: The girl's mother, great-grandmother, and grandmother's brother also had a prominent forehead, triangular face, and severely proportional dwarfism but no limb asymmetry or adrenal insufficiency. Exome sequencing of the girl revealed a new heterozygous CDKN1C (NM_000076. 2) c.836G>A mutation, resulting in a variant with a predicted evolutionarily highly conserved arginine substituted by histidine (p.Arg279His). The same causative mutation was found in both the proband's mother, great-grandmother, and grandmother's brother, who had similar phenotypes. Thus far, we found an SRS pedigree, which was due to a missense mutation affecting the same amino acid position, 279, in the CDKN1C gene, resulting in the amino acid substitution p.Arg279His (c.836G>A). Although the SRS-related CDKN1C mutation is in the IMAGe-related mutation hotspot region [the proliferating cell nuclear antigen (PCNA) domain], no adrenal insufficiency was reported in this SRS pedigree. The reason may be that the location of the genomic mutation and the type of missense mutation determines the phenotype. The proband was treated with recombinant human growth hormone (rhGH). After 1 year of rhGH treatment, the height standard deviation score of the proband increased by 0.93 standard deviation score, and her growth rate was 8.1 cm/year. No adverse reactions, such as abnormal blood glucose, were found. Functional mutations in CDKN1C can lead to familial SRS without limb asymmetry, and some patients may have glucose abnormalities. In familial SRS patients, the PCNA region of CDKN1C should be analysed. Adrenal insufficiency should be excluded in all patients with functional CDKN1C variants. IMAGe syndrome is an acronym for the major findings of intrauterine growth restriction (IUGR), metaphyseal dysplasia, adrenal hypoplasia congenita, and genitourinary abnormalities (in males). Findings reported in individuals with a clinical and/or molecular diagnosis include: IUGR; Some type of skeletal abnormality (most commonly delayed bone age and short stature, and occasionally, metaphyseal and epiphyseal dysplasia of varying severity); Adrenal insufficiency often presenting in the first month of life as an adrenal crisis or (rarely) later in childhood with failure to thrive and recurrent vomiting; Genital abnormalities in males (cryptorchidism, micropenis, and hypospadias) but not in females. Hypotonia and developmental delay are reported in some individuals; cognitive outcome appears to be normal in the majority of individuals. The diagnosis of IMAGe syndrome is established in a proband with suggestive findings and/or a heterozygous CDKN1C pathogenic variant in the PCNA (proliferating cell nuclear antigen)-binding domain of the maternally expressed allele identified by molecular genetic testing. Treatment of manifestations: Management of adrenal insufficiency in IMAGe syndrome is similar to management of adrenal insufficiency from other causes and should be under the supervision of an endocrinologist. Chronic treatment includes replacement doses of glucocorticoids and mineralocorticoids and oral sodium chloride supplements. Steroid doses should be optimized to allow for linear growth without risking an adrenal crisis. Consider assessment for growth hormone deficiency to determine if growth hormone should be considered. Routine management of cryptorchidism and hypospadias by a urologist, and routine hormone replacement by an endocrinologist for hypogonadotropic hypogonadism. Management by an orthopedist as needed for skeletal complications such as scoliosis and hip dysplasia. Occupational, speech, and/or physical therapy as needed, particularly in those with hypotonia. Surveillance: Growth assessment at each visit; annual evaluations by an endocrinologist to monitor adrenal function and for development of hypercalciuria and nephrocalcinosis; evaluation as needed by an orthopedist to monitor for skeletal complications as needed; assessment of hypotonia, developmental progress, and educational needs at each visit. Evaluation of relatives at risk: To allow early diagnosis and management of adrenal insufficiency in at-risk newborns, molecular genetic testing should be pursued if the CDKN1C pathogenic variant in the family is known; if the familial pathogenic variant is not known, screen for serum electrolyte abnormalities, elevated serum ACTH level, and skeletal features of IMAGe syndrome. Pregnancy management: Risks to a mother with IMAGe syndrome during pregnancy include possible adrenal insufficiency; risks during delivery include cephalopelvic disproportion. Typically, a CDKN1C pathogenic variant causing IMAGe syndrome is inherited in an autosomal dominant manner; however, only maternal transmission of the pathogenic variant results in IMAGe syndrome. Each child of a woman with a heterozygous pathogenic CDKN1C variant has a 50% chance of inheriting the variant and being affected. Each child of a man with a heterozygous pathogenic CDKN1C variant has a 50% chance of inheriting the variant but is expected to be unaffected. If the pathogenic variant has been identified in an affected family member, prenatal testing is possible for a pregnancy at increased risk (i.e., when the mother has the pathogenic variant).

Loss-of-function mutations in CDKN1C cause overgrowth, that is, Beckwith-Wiedemann syndrome (BWS), while gain-of-function variants in the gene's PCNA binding motif cause a growth-restricted condition called IMAGe syndrome. We report on a boy with a remarkable mixture of both syndromes, with developmental delay and microcephaly as additional features. Whole-exome DNA sequencing and ultra-deep RNA sequencing of leucocyte-derived and fibroblast-derived mRNA were performed in the family. We found a maternally inherited variant in the IMAGe hotspot region: NM_000076.2(CDKN1C) c.822_826delinsGAGCTG. The asymptomatic mother had inherited this variant from her mosaic father with mild BWS features. This delins caused tissue-specific frameshifting resulting in at least three novel mRNA transcripts in the boy. First, a splice product causing CDKN1C truncation was the likely cause of BWS. Second, an alternative splice product in fibroblasts encoded IMAGe-associated amino acid substitutions. Third, we speculate that developmental delay is caused by a change in the alternative CDKN1C-201 (ENST00000380725.1) transcript, encoding a novel isoform we call D (UniProtKB: A6NK88). Isoform D is distinguished from isoforms A and B by alternative splicing within exon 1 that changes the reading frame of the last coding exon. Remarkably, this delins changed the reading frame back to the isoform A/B type, resulting in a hybrid D-A/B isoform. Three different cell-type-dependent RNA products can explain the co-occurrence of both BWS and IMAGe features in the boy. Possibly, brain expression of hybrid isoform D-A/B is the cause of developmental delay and microcephaly, a phenotypic feature not previously reported in CDKN1C patients.