# February 2026

- Link: https://isnr.in/february-2026/
- Published: 2026-02-11T01:50:29+05:30
- Author: ISNR

## CASE HISTORY

A term, appropriate-for-gestational-age neonate with **normal APGAR scores** and**
no history of perinatal hypoxia** presented with **seizures on day 2 of life**. 
There were no antenatal or perinatal complications. Initial consideration was hypoxic–
ischemic encephalopathy (HIE); however, the clinical history was discordant with
this diagnosis.

## CASE CONTRIBUTED BY

Dr **Thapasya**, DNB resident, KMCH, Coimbatore

![](https://isnr.in/wp-content/uploads/2026/02/case-of-the-month-february-2026-1.
jpg)

**DWI**: **Diffuse, symmetric cortical thickening with widespread diffusion restriction**,
involving bilateral cortical and subcortical regions, **basal ganglia**, **thalami**,
and **cerebral peduncles**.

**SWI**: Susceptibility-weighted imaging shows no hemorrhage

#### **MRI Spectrum**

**Acute:** Diffuse white matter and caudate T2 hyperintensity with widespread diffusion
restriction; MRS shows **elevated lactate and reduced NAA**.
**Subacute:** **T1/
T2 shortening of basal ganglia**, mimicking HIE, with relative thalamic sparing.**
Chronic:** **Severe volume loss** of basal ganglia and white matter with **cystic
degeneration**.

#### **Imaging Differentials:**

HIE-like metabolic disorders (MoCD/ISOD)
Epileptic encephalopathyMitochondrial cytopathy.

## **Diagnosis**: Targeted metabolic evaluation followed by **genetic testing confirmed molybdenum cofactor deficiency**.

LIKELY COMPOUND HETEROZYGOUS VARIANTS TO BE CAUSATIVE OF THE REPORTED PHENOTYPE 
WERE IDENTIFIED

| **Gene (Transcript)** | **Location** | **Variant** | **Zygosity** | **Disease (OMIM)** | **Inheritance** | **Classification** | 
| MOCSI (-)
(ENST00000373186.4) | Exon 7 | c.955C>T(p.Arg319Ter) | Heterozygous | Molybdenumcolactor deficiencyofcomplementationgroup A | Autosomalrecessive | Pathogenic | 
|  | Exon 1 | c.217C>T(p.Arg73Trp) | Heterozygous |  |  | Likely Pathogenic |

**“Reclassification of these variants could be considered based on parental testing.”**

#### **Discussion**:

Hypoxic–ischemic encephalopathy (HIE) is the most common cause of neonatal encephalopathy.
MoCD leads to toxic sulfite accumulation, resulting in severe excitotoxic neuronal
injury and HIE-like imaging patterns, often in the absence of a hypoxic insult.

#### **Conclusion:**

MoCD is a HIE-like imaging patterns that are discordant with clinical history, thucritical
metabolic mimic of HIE. Imaging plays a pivotal role in identifying molybdenum cofactor
deficiency by recognizing s guiding timely metabolic and genetic testing, preventing
misdiagnosis.

| **Feature** | **HIE** | **MOCD** | 
| **Perinatal hypoxia** | Present | Absent | 
| **DWI pattern** | Watershed/deep nuclei | Diffuse, non-vascular | 
| **Brainstem (cerebral peduncles)** | Spared | Involved (hallmark) | 
| **SWI microbleeds** | Rare | Absent | 
| **Evolution** | Cystic encephalomalacia | Rapid atrophy, no cysts | 
| **MRS** | ↑Lactate | ↓↓NAA, ↑Lactate, ↑Glutamine |