Liang-Wang syndrome (LIWAS) is a polymalformative syndrome first described in 2019 caused by heterozygous mutation of the KCNMA1 gene encoding the Ca²⁺ and voltage-activated K⁺ channel (BKC). The KCNMA1 variant p.(Gly356Arg) abolishes the function of BKC and blocks the generation of K⁺ current. The phenotype of this variant includes developmental delay, and visceral and connective tissue malformations. So far, only three cases of LWAS have been described, one of which also had neonatal diabetes (ND). We present the case of a newborn affected by LIWAS carrying the p.(Gly375Arg) variant who manifested diabetes in the first week of life. The description of our case strongly increases the frequency of ND in LIWAS patients and suggests a role of BK inactivation in human insulin secretion. The knowledge on the role of BKC in insulin secretion is very poor. Analyzing the possible mechanisms that could explain the association of LIWAS with ND, we speculate that BK inactivation might impair insulin secretion through the alteration of ion-dependent membrane activities and mitochondrial functions in β-cells, as well as the impaired intra-islet vessel reactivity.

The bloody stools of newborns may be a clue for several clinical entities of varying severity, ranging from idiopathic neonatal transient colitis to food-protein-induced allergic proctocolitis (FPIAP) or necrotizing enterocolitis (NEC). Distinguishing among them at an early stage is challenging but crucial, as the treatments and prognoses are different. We conducted a monocentric retrospective study including all pre-term infants with bloody stools admitted to the Neonatal Intensive Care Unit (NICU) of the Vittore Buzzi Children’s Hospital (Milan) from December 2022 to May 2024. Patients diagnosed with NEC exhibited significantly lower eosinophil counts and higher procalcitonin levels than both patients with FPIAP and patients with idiopathic neonatal transient colitis, as well as a statistically significant increase in pathological features from abdomen ultrasounds and abdominal X-rays. In contrast, no lab markers or imaging techniques have been demonstrated to be useful in distinguishing between idiopathic neonatal transient colitis and FPIAP. Thus, after excluding a diagnosis of NEC, the only way to confirm FPIAP is through the oral food challenge, which can be performed in premature newborns presenting with bloody stools who are otherwise healthy and under medical supervision, in order to identify infants who may benefit from a cow’s-milk-free diet.

Bloody stools in the newborn may be a clue for several clinical entities of varying severity ranging from a transient hematochezia to food protein induced allergic proctocolitis (FPIAP) or necrotizing enterocolitis (NEC). To distinguish among them at an early stage is challenging, but crucial, as the treatment and prognosis are different. We conducted a monocentric retrospective study including all preterm infants admitted to the NICU of the Vittore Buzzi Children’s Hospital (Milan) with bloody stools from December 2022 to May. Patients diagnosed with NEC exhibited a significantly lower eosinophil count and higher procalcitonin levels than both patients with CMPA and patients with transient hematochezia, as well as a statistically significant increase in pathological features at abdomen ultrasounds and abdominal X-rays. In contrast, no Lab markers or imaging have been demonstrated to be useful in distinguishing between transient hematochezia and FPIAIP. Thus, after excluding a diagnosis of NEC the only way to confirm the FPIAP is the oral food challenge, which can be performed even in premature newborns presenting blood stools, otherwise healthy, under medical supervision, in order to identify infants who may benefit from a cow’s milk free diet.